l-dehydroascorbic acid

l-dehydroascorbic acid (de-hi′dro-as-kor′bik)

The reversibly oxidized form of ascorbic acid; it is antiscorbutic, but is converted in the body to 2,3-diketo-l-gulonic acid, which has no vitamin C activity.

l-dopa
l-dopa

SYN: levodopa.

l-glyceric aciduria
l-glyceric aciduria

Excretion of l-glyceric acid in the urine; a primary metabolic error due to deficiency of d-glyceric dehydrogenase resulting in excretion of l-glyceric and oxalic acids, leading to the clinical syndrome of oxalosis with frequent formation of oxalate renal calculi.

l-gulonic acid
l-gulonic acid (goo-lon′ik)

Reduction product of glucuronic acid (–CHO → &cbond;CH₂OH); oxidation product of l-gulose (–CHO → &cbond;COOH); a precursor (except in certain primates, guinea pigs, certain fishes, and the Indian fruit bat) of ascorbic acid via l-gulonolactone.

l-gulonolactone
l-gulonolactone (goo-lon′o-lak-ton)

The immediate precursor of ascorbic acid in those animals capable of ascorbic acid biosynthesis. SYN: dihydroascorbic acid, l-gulono-γ-lactone.
l-gulonolactone oxidase the enzyme catalyzing the conversion of l-gulonolactone and O₂ to H₂O₂ and l-xylo-hexulonolactone, a precursor of ascorbic acid; absent in humans.

l-gulono-γ-lactone
l-gulono-γ-lactone

SYN: l-gulonolactone.

3-l-hydroxykynurenine
3-l-hydroxykynurenine (hi-drok′se-ki-noo-re-nen)

An intermediate in the catabolism of l-tryptophan and a precursor of xanthurenate; elevated in cases of a vitamin B₆ deficiency.

Λ
Λ

1. The 11th letter of the Greek alphabet, lambda. 2. Symbol (λ) for Avogadro number; wavelength; radioactive constant; Ostwald solubility coefficient; molar conductivity of an electrolyte (Λ). 3. In chemistry, denotes the position of a substituent located on the eleventh atom from the carboxyl or other functional group (λ).

L
L

1. Abbreviation for left ( e.g., left eye); lumbar vertebrae (L1 to L5). 2. Symbol for inductance; liter; leucine; leucyl. 3. Abbreviation for limes; used with a lower case letter, plus sign, subscript letter, or subscript plus sign as a symbol for various doses of toxin. See dose.

L
L

Symbol for linking number.

l
l

Symbol for liter; liquid; length (in italics).

l- l-

Levorotatory. Cf.:d-. [L. laevus, on the left-hand side]

l- l-

Prefix indicating a chemical compound to be structurally (sterically) related to l-glyceraldehyde. Cf.:d-.

La
La

Symbol for lanthanum.

Laband
Laband

Peter F., U.S. dentist, *1900. See L. syndrome.

Labbé
Labbé

Ernest M., French physician, 1870–1939.

Labbé
Labbé

Leon, French surgeon, 1832–1916. See Labbé triangle, Labbé vein.

label
label

1. To incorporate into a compound a substance that is readily detected, such as a radionuclide, whereby its metabolism can be followed or its physical distribution detected. 2. The substance so incorporated.

la belle indifférence
la belle indifférence (lah bel an-dif-er-ahns′)

A naive, inappropriate lack of emotion or concern for the perceptions by others of one's disability, typically seen in persons with conversion hysteria. [Fr.]

labetalol hydrochloride
labetalol hydrochloride (la-bet′a-lol)

An α-adrenergic and β-adrenergic blocking agent used in the treatment of hypertension.

labia
labia (la′be-a)

Plural of labium.

labial
labial (la′be-al)

1. Relating to the lips or any labium. 2. Toward a lip. 3. One of the letters formed by means of the lips. [L. labium, lip]

labialism
labialism (la′be-al-izm)

A form of stammering in which there is confusion in the use of the labial consonants.

labially
labially (la′be-al-e)

Toward the lips.

labile
labile (la′bil, -bil)

Unstable; unsteady, not fixed; denoting: 1. An adaptability to alteration or modification, i.e., relatively easily changed or rearranged. 2. Certain constituents of serum affected by increases in heat. 3. An electrode that is kept moving over the surface during the passage of an electric current. 4. In psychology or psychiatry, denoting free and uncontrolled mood or behavioral expression of the emotions. 5. Easily removable; e.g., a l. hydrogen atom. [L. labilis, liable to slip, fr. labor, pp. lapsus, to slip]

lability
lability (la-bil′i-te)

The state of being labile.

labio- labio-

The lips. SEE ALSO: cheilo-. [L. labium, lip]

labiocervical
labiocervical (la′be-o-ser′vi-kal)

Relating to a lip and a neck; specifically, to the labial or buccal surface of the neck of a tooth. [labio- + L. cervix, neck]

labioclination
labioclination (la′be-o-kli-na′shun)

Inclination of position more toward the lips than is normal; said of a tooth.

labiodental
labiodental (la-be-o-den′tal)

Relating to the lips and the teeth; denoting certain letters the sound of which is formed by both lips and teeth. [labio- + L. dens, tooth]

labiogingival
labiogingival (la′be-o-jin′ji-val)

Relating to the point of junction of the labial border and the gingival line on the distal or mesial surface of an incisor tooth.

labioglossolaryngeal
labioglossolaryngeal (la′be-o-glos′o-la-rin′je-al)

Relating to the lips, tongue, and larynx; describing bulbar paralysis in which these parts are involved. [labio- + G. glossa, tongue, + larynx]

labioglossopharyngeal
labioglossopharyngeal (la′be-o-glos′o-fa-rin′je-al)

Relating to the lips, tongue, and pharynx; describing bulbar paralysis involving these parts. [labio- + G. glossa, tongue, + pharynx]

labiograph
labiograph (la′be-o-graf)

An instrument for recording the movements of the lips in speaking. [labio- + G. grapho, to record]

labiomental
labiomental (la′be-o-men′tal)

Relating to the lower lip and the chin. [labio- + L. mentum, chin]

labionasal
labionasal (la′be-o-na′sal)

1. Relating to the upper lip and the nose, or to both lips and the nose. 2. Denoting a letter that is both labial and nasal in the production of its sound.

labiopalatine
labiopalatine (la′be-o-pal′a-tin)

Relating to the lips and the palate.

labioplacement
labioplacement (la′be-o-plas′ment)

Positioning ( e.g., of a tooth) more toward the lips than normal.

labioplasty
labioplasty (la′be-o-plas-te)

Plastic surgery of a lip. [labio- + G. plastos, formed]

labioversion
labioversion (la′be-o-ver-zhun)

Malposition of an anterior tooth from the normal line of occlusion toward the lips.

labitome
labitome (lab′i-tom)

A forceps with sharp blades. SYN: cutting forceps. [G. labis, pincers, + tome, an incision]

labium
labium, gen. labii, pl .labia (la′be-um, -be-e, -be-a) [TA]

1. SYN: lip. 2. Any lip-shaped structure. [L.]
l. anterius ostii uteri [TA] SYN: anterior lip of external os of uterus.
l. externum cristae iliacae [TA] SYN: outer lip of iliac crest.
l. inferius oris [TA] SYN: lower lip.
l. internum cristae iliacae [TA] SYN: inner lip of iliac crest.
l. laterale lineae asperae [TA] SYN: lateral lip of linea aspera.
l. limbi tympanicum laminae spiralis ossei SYN: tympanic lip of spiral limbus.
l. limbi tympanicum limbi spiralis ossei [TA] SYN: tympanic lip of spiral limbus.
l. limbi vestibulare laminae spiralis ossei SYN: vestibular lip of spiral limbus.
l. limbi vestibulare limbi spiralis ossei [TA] SYN: vestibular lip of spiral limbus.
l. majus [TA] one of two rounded folds of integument forming the lateral boundaries of the pudendal cleft. The labia majora are the female homolog of the scrotum. SYN: l. majus pudendi [TA] , large pudendal lip.
l. majus pudendi, pl .labia majora [TA] SYN: l. majus.
l. mediale lineae asperae [TA] SYN: medial lip of linea aspera.
l. minus [TA] one of two narrow longitudinal folds of mucous membrane enclosed in the pudendal cleft within the labia majora; posteriorly, they gradually merge into the labia majora and join to form the frenulum labiorum pudendi (fourchette); anteriorly, each l. divides into two portions that unite with those of the opposite side in front of the glans clitoridis to form the prepuce. SYN: l. minus pudendi, small pudendal lip.
l. minus pudendi, pl .labia minora SYN: l. minus.
labia oris [TA] SYN: lips of mouth, under lip. See lip (1) .
l. posterius ostii uteri [TA] SYN: posterior lip of external os of uterus.
l. superius oris [TA] SYN: upper lip.
tympanic l. of limbus of spiral lamina SYN: tympanic lip of spiral limbus.
l. urethrae one of the two lateral margins of the external urethral orifice of the female.
labia uteri anterior lip of external os of uterus, posterior lip of external os of uterus.
vestibular l. of limbus of spiral lamina SYN: vestibular lip of spiral limbus.
l. vocale, pl .labia vocalia SYN: vocal fold.

labor
labor (la′bor)

The process of expulsion of the fetus and the placenta from the uterus. The stages of l. include: first stage, beginning with the onset of uterine contractions through the period of dilation of the os uteri; second stage, the period of expulsive effort, beginning with complete dilation of the cervix and ending with expulsion of the infant; third s. or placental stage, the period beginning at the expulsion of the infant and ending with the completed expulsion of the placenta and membranes. [L. toil, suffering]
active l. contractions resulting in progressive effacement and dilation of the cervix.
dry l. obsolete term for l. after spontaneous loss of the amniotic fluid.
false l. contractions which do not produce cervical dilation or effacement.
missed l. brief uterine contractions which do not lead to l. and expulsion of the infant, but which cease, resulting in the indefinite retention of the fetus (usually lifeless) either in utero or in the abdominal cavity.
precipitate l. very rapid l. ending in delivery of the fetus.
premature l. onset of l. after 20 weeks and before the 37th completed week of pregnancy dated from the last normal menstrual period.
trial of l. after cesarean section the attempt to deliver vaginally after a cesarean section; carries some risk of rupture of the uterine scar.

laboratorian
laboratorian (lab′o-ra-tor′e-an)

One who works in a laboratory; in the medical and allied health professions, one who examines or performs tests (or supervises such procedures) with various types of chemical and biologic materials, chiefly as an aid in the diagnosis, treatment, and control of disease, or as a basis for health and sanitation practices.

laboratory
laboratory (lab′o-ra-to-re, lab′ra-)

A place equipped for the performance of tests, experiments, and investigative procedures and for the preparation of reagents, therapeutic chemical materials, and so on. [Mediev. L. laboratorium, a workplace, fr. L. laboro, pp. -atus, to labor]
personal growth l. a sensitivity training setting in which the primary emphasis is on each participant's potentialities for creativity, empathy, and leadership. SEE ALSO: sensitivity training group.

labra
labra (la′bra)

Plural of labrum. [L.]

labrale inferius
labrale inferius (la-bra′le in-fe′re-us)

A point where the boundary of the vermilion border of the lower lip and the skin is intersected by the median plane.

labrale superius
labrale superius (la-bra′le soo-pe′re-us)

The point on the upper lip lying in the median sagittal plane on a line drawn across the boundary of the vermilion border and skin.

labrocyte
labrocyte (lab′ro-sit)

SYN: mast cell.

labrum
labrum, pl .labra (la′brum, la′bra) [TA]

1. A lip. 2. A lip-shaped structure. 3. A fibrocartilaginous lip around the margin of the concave portion of some joints. SYN: articular l., articular lip, l. articulare. [L.]
acetabular l. [TA] a fibrocartilaginous rim attached to the margin of the acetabulum of the hip bone. SYN: l. acetabulare [TA] , acetabular lip, circumferential cartilage (1) , cotyloid ligament, ligamentum cotyloideum.
l. acetabulare [TA] SYN: acetabular l..
articular l. SYN: l. (3) .
l. articulare SYN: l. (3) .
l. glenoidale scapulae [TA] SYN: glenoid l. of scapula.
glenoid l. of scapula [TA] a ring of fibrocartilage attached to the margin of the glenoid cavity of the scapula to increase its depth. SYN: l. glenoidale scapulae [TA] , articular margin, circumferential cartilage (2) , glenoid ligament (1) , glenoidal lip, ligamentum glenoidale.

labyrinth
labyrinth (lab′i-rinth) [TA]

Any of several anatomic structures with numerous intercommunicating cells or canals. 1. The internal or inner ear, composed of the semicircular ducts, vestibule, and cochlea. 2. Any group of communicating cavities, as in each lateral mass of the ethmoid bone. 3. A group of upright test tubes terminating below in a base of communicating, alternately ∪-shaped and ∩-shaped tubes, used for isolating motile from nonmotile organisms in culture, or a motile from a less motile organism (as the typhoid from the colon bacillus), the former traveling faster and farther through the tubes than the latter.
bony l. [TA] a series of cavities (cochlea, vestibule, and semicircular canals) contained within the otic capsule of the petrous portion of the temporal bone; the bony l. is filled with perilymph, in which the delicate, endolymph-filled membranous l. is suspended. SYN: labyrinthus osseus [TA] , osseous l..
cochlear l. [TA] the portion of the membranous l. concerned with the sense of hearing (vs. the vestibular l., which is concerned with the sense of equilibration) and innervated by the cochlear nerve; it is located within the cochlea of the bony l., and consists of the cochlear duct, which contains the spiral organ. SYN: labyrinthus cochlearis [TA] , organ of hearing.
ethmoidal l. [TA] a mass of air cells with thin bony walls forming part of the lateral wall of the nasal cavity; the cells are arranged in three groups, anterior, middle, and posterior, and are closed laterally by the orbital plate which forms part of the wall of the orbit. SYN: labyrinthus ethmoidalis [TA] , ectethmoid, ectoethmoid, lateral mass of ethmoid bone.
Ludwig l. SYN: convoluted part of kidney lobule.
membranous l. [TA] a complex arrangement of communicating membranous canaliculi and sacs, filled with endolymph and surrounded by perilymph, suspended within the cavity of the bony l.; its chief divisions are the cochlear duct and the vestibular l.. SYN: labyrinthus membranaceus [TA] .
osseous l. SYN: bony l..
renal l. SYN: convoluted part of kidney lobule.
Santorini l. SYN: prostatic venous plexus.
vestibular l. [TA] the portion of the membranous l. concerned with the sense of equilibration (vs. the cochlear l., which is concerned with the sense of hearing) and innervated by the vestibular nerve; it is located within the semicircular canals and vestibule of the bony l., and consists of the utricle, saccule, and the semicircular, utriculosaccular, and endolymphatic ducts. SYN: labyrinthus vestibularis [TA] , vestibular organ.

labyrinthectomy
labyrinthectomy (lab-i-rin-thek′to-me)

Excision of the labyrinth; a destructive operation to destroy labyrinthine function. [labyrinth + G. ektome, excision]

labyrinthine
labyrinthine (lab-i-rin′thin)

Relating to any labyrinth.

labyrinthitis
labyrinthitis (lab′i-rin-thi′tis)

Inflammation of the labyrinth (the internal ear), sometimes accompanied by vertigo and deafness. SYN: otitis interna.

labyrinthotomy
labyrinthotomy (lab-i-rin-thot′o-me)

Incision into the labyrinth. [labyrinth + G. tome, incision]

labyrinthus
labyrinthus (lab-i-rin′thus)

SYN: convoluted part of kidney lobule. [L. fr. G. labyrinthos, labyrinth]
l. cochlearis [TA] SYN: cochlear labyrinth.
l. ethmoidalis [TA] SYN: ethmoidal labyrinth.
l. membranaceus [TA] SYN: membranous labyrinth.
l. osseus [TA] SYN: bony labyrinth.
l. vestibularis [TA] SYN: vestibular labyrinth.

lac
lac, gen. lactis (lak, lak′tis)

1. SYN: milk (1) . 2. Any whitish, milklike liquid. [L. milk]
l. sulfuris SYN: precipitated sulfur.
l. vaccinum cow's milk.

lacca
lacca (lak′a)

SYN: shellac.

laccase
laccase (lak′as)

An enzyme oxidizing benzenediols to semiquinones with O₂. SYN: monophenol monooxygenase (2) , phenol oxidase, phenolase, polyphenol oxidase, urushiol oxidase.

lacerable
lacerable (las′er-a-bl)

Capable of being, or liable to be, torn. [L. lacero, to tear to pieces, fr. lacer, mangled]

lacerated
lacerated (las′er-a-ted)

Torn; rent; having a ragged edge. [L. lacero, pp. -atus, to tear to pieces]

laceration
laceration (las-er-a′shun)

1. A torn or jagged wound, or an accidental cut wound. 2. The process or act of tearing the tissues. [L. lacero, pp. -atus, to tear to pieces]
brain l. gross tearing of neural tissue.
scalp l. a tear of the dermis or underlying tissues and galea aponeurotica of the scalp.
through-and-through l. a l. that penetrates two surfaces of a structure, generally restricted to skin or mucosal surfaces, such as the cheek, lip, ala nasi, pinna, etc.
vaginal l. tearing of the vaginal wall. SYN: colporrhexis.

lacertus
lacertus (la-ser′tus) [TA]

1. [TA] A fibrous band, bundle, or slip related to a muscle. 2. Originally the muscular part of the upper limb from shoulder to elbow. [L.]
l. cordis one of the trabeculae carneae.
l. fibrosus bicipital aponeurosis.
l. of lateral rectus muscle the part of the tendon of origin of the lateral rectus muscle attaching to the greater wing of the sphenoid bone, lateral to the common tendinous ring; often incorrectly equated to the lateral check ligament of the eyeball. SYN: l. musculi recti lateralis.
l. medius SYN: anterior longitudinal ligament.
l. musculi recti lateralis SYN: l. of lateral rectus muscle.

lachrymal
lachrymal (lak′ri-mal)

SYN: lacrimal.

LACI
LACI

Abbreviation for lipoprotein-associated coagulation inhibitor.

laciniae tubae
laciniae tubae (la-sin′e-e too′be)

SYN: fimbriae of uterine tube, under fimbria. [L. lacinia, fringe]

lacrimal
lacrimal (lak′ri-mal)

Relating to the tears, their secretion, the secretory glands, and the drainage apparatus. SYN: lachrymal. [L. lacrima, a tear]

lacrimation
lacrimation (lak′ri-ma′shun)

The secretion of tears, especially in excess. [L. lacrimatio]

lacrimator
lacrimator (lak′ri-ma-ter)

An agent (such as tear gas) that irritates the eyes and produces tears. [L. lacrima, tear]

lacrimatory
lacrimatory (lak′ri-ma-to-re)

Causing lacrimation.

lacrimotomy
lacrimotomy (lak-ri-mot′o-me)

The operation of incising the lacrimal duct or sac. [L. lacrima, tear, + G. tome, incision]

lact- lact-, lacti-, lacto-

Milk. SEE ALSO: galacto-. [L. lac, lactis]

lactacidemia
lactacidemia (lak-tas-i-de′me-a)

SYN: lactic acidemia.

lactacidosis
lactacidosis (lak-tas-i-do′sis)

Acidosis due to increased lactic acid.

lactalbumin
lactalbumin (lak-tal-bu′min)

The albumin fraction of milk. It contains two proteins: α- and β-l.; the former, minor l., interacts with galactosyl transferase to form lactose synthase which synthesizes lactose from d-glucose and UDP-galactose in milk production; β-l. is the chief whey protein in bovine milk; α-l. is the most heat-stable of the whey proteins.

lactam
lactam, lactim (lak′tam, -tim)

Contractions of “lactoneamine” and “lactoneimine,” and applied to the tautomeric forms –NH–CO– and –N&dbond;C(OH)–, respectively, observed in many purines, pyrimidines, and other substances; the latter form accounts for the acidic properties of uric acid.

lactamase
lactamase (lak′ta-maz)

SYN: β-l..

lactase
lactase (lak′tas)

SYN: β-d-galactosidase.

lactate
lactate (lak′tat)

1. A salt or ester of lactic acid. 2. To produce milk in the mammary glands.
l. dehydrogenase (LDH) name for a number of enzymes, including: l-l. dehydrogenase (cytochrome), d-l. dehydrogenase (cytochrome), l-l. dehydrogenase, and d-l. dehydrogenase. The first two enzymes transfer hydrogen to ferricytochrome c or to cytochrome b₂, the last two enzymes transfer it to NAD⁺, in catalyzing the oxidation of l. to pyruvate; the isozyme distribution of heart and muscle l. dehydrogenase is of significant use in cases of myocardial infarction; a deficiency of a subunit will result in myoglobinuria after intense exercise. SYN: lactic acid dehydrogenase.
excess l. the increase in l. concentration beyond what would be expected from the increase in pyruvate concentration resulting from a change in redox potential; used as an index of anaerobic carbohydrate metabolism.
Ringer l. SYN: Ringer solution.

lactate 2-mono-oxygenase
lactate 2-mono-oxygenase

A flavoprotein oxidoreductase catalyzing oxidation (with O₂) of l-lactate to acetate plus CO₂ and water. SYN: lactic acid oxidative decarboxylase.

lactation
lactation (lak-ta′shun)

1. Production of milk. 2. Period following birth during which milk is secreted in the breasts. [L. lactatio, suckle]

lactational
lactational (lak-ta′shun-al)

Relating to lactation.

lacteal
lacteal (lak′te-al)

1. Relating to or resembling milk; milky. 2. A lymphatic vessel that conveys chyle. SYN: chyle vessel, l. vessel.
central l. the blindly ending lymphatic capillary in the center of an intestinal villus.

lactenin
lactenin (lak′te-nin)

An antibacterial agent active against streptococci isolated from cow's milk.

lactescent
lactescent (lak-tes′ent)

Resembling milk; milky.

lacti- lacti-

See lact-.

lactic
lactic (lak′tik)

Relating to milk. [L. lac (lact-), milk]

lactic acid
lactic acid

A normal intermediate in the fermentation (oxidation, metabolism) of sugar. In pure form, a syrupy, odorless, and colorless liquid obtained by the action of the l. bacillus on milk or milk sugar; in concentrated form, a caustic used internally to prevent gastrointestinal fermentation. A culture of the bacillus, or milk containing it, is usually given in place of the acid. l-L. is also known as sarcolactic acid.

lactic acid dehydrogenase
lactic acid dehydrogenase

SYN: lactate dehydrogenase.

lactic acidemia
lactic acidemia (lak′tik-as-i-de′me-a)

The presence of dextrorotatory lactic acid in the circulating blood. SYN: lactacidemia. [lactic acid + G. haima, blood]

lactic acid oxidative decarboxylase
lactic acid oxidative decarboxylase

SYN: lactate 2-mono-oxygenase.

lactiferous
lactiferous (lak-tif′er-us)

Yielding milk. [lacti- + L. fero, to bear]

lactifugal
lactifugal (lak-tif′u-gal)

SYN: lactifuge (1) .

lactifuge
lactifuge (lak′ti-fuj)

1. Causing arrest of the secretion of milk. SYN: lactifugal. 2. An agent having such an effect. [lacti- + L. fugo, to drive away]

lactigenous
lactigenous (lak-tij′e-nus)

Producing milk. [lacti- + -gen, producing]

lactim
lactim (-tim)

See lactam.

lactimorbus
lactimorbus (lak-ti-mor′bus)

SYN: milk sickness. [lacti- + L. morbus, disease]

lactinated
lactinated (lak′ti-na-ted)

Prepared with or containing milk sugar.

lacto- lacto-

See lact-.

Lactobacillaceae
Lactobacillaceae (lak′to-bas′i-la′se-e)

A family of anaerobic to facultatively anaerobic, ordinarily nonmotile bacteria (order Eubacteriales) containing straight or curved, Gram-positive rods which usually occur singly or in chains; motile cells are peritrichous. These organisms have complex organic nutritional requirements; they produce lactic acid from carbohydrates. They are found in fermenting animal and plant products where carbohydrates are available; they are also found in the mouth, vagina, and intestinal tract of various warm-blooded animals, including humans. Only a few species are pathogenic. The type genus is Lactobacillus, which contains 56 species.

lactobacilli
lactobacilli (lak-to-ba-sil′i)

Plural of lactobacillus.

lactobacillic acid
lactobacillic acid (lak′to-ba-sil′ik)

A major constituent of the lipids of lactobacilli; notable for the presence of a cyclopropane ring in the molecule.

Lactobacillus
Lactobacillus (lak-to-ba-sil′us)

A genus of microaerophilic or anaerobic, nonsporeforming, ordinarily nonmotile bacteria (family Lactobacillaceae) containing Gram-positive curved or straight rods that vary from long and slender cells to short coccobacilli; chains are commonly produced especially in the later part of the logarithmic phase of growth. These organisms possess complex nutritional requirements, generally characteristic for each species; metabolism is fermentative and at least half of the end product is lactic acid. They are found in dairy products, effluents of grain and meat products, water, sewage, beer, wine, fruits and fruit juices, pickled vegetables, and in sourdough and mash, and are part of the normal flora of the mouth, intestinal tract, and vagina of many warm-blooded animals, including humans; as normal flora, they produce bacterocidins protective against pathogenic bacteria; rarely are they pathogenic. The type species is L. delbrueckii. [lacto- + bacillus]
L. acidophilus a bacterial species found in the feces of milk-fed infants and also in the feces of older persons on a high milk-, lactose-, or dextrin-containing diet.
L. brevis a bacterial species widely distributed in nature, especially in plant and animal products; it is also found in the mouth and intestinal tract of humans and rats.
L. buchneri a bacterial species widely distributed in fermenting substances.
L. bulgaricus a bacterial species used in the production of yogurt.
L. casei a bacterial species found in milk and cheese.
L. catenaformis an anaerobic bacterial species found in the intestines and pulmonary cavities of humans.
L. crispatus a bacterial species found in pus from a dental abscess.
L. curvatus a bacterial species found in cow dung, dairy barn air, silage, milk, and in a case of endocarditis.
L. delbrueckii a bacterial species found in fermenting vegetables and grain mashes; it is the type species of the genus L..
L. fermentum a bacterial species found widely distributed in nature, especially in fermenting plant and animal products. Also found in the mouth of human beings.
L. jensenii a bacterial species isolated from human sources such as vaginal discharge and blood clot.
L. plantarum a bacterial species found in dairy products and environments, fermenting plants, silage, sauerkraut, pickled vegetables, spoiled tomato products, sour dough, cow dung, and the human mouth, intestinal tract, and stools.
L. salivarius a bacterial species found in the mouth and intestinal tract of the hamster, the mouth of humans, and the intestinal tract of the hen.
L. trichodes a bacterial species found in wines containing 20% ethanol and in lees in California, Australia, France, and Spain; in California this organism is commonly referred to as the hair bacillus, cottony bacillus, cottony mold, or Fresno mold.

lactobacillus
lactobacillus (lak-to-ba-sil′us)

A vernacular term used to refer to any member of the genus L..

lactobezoar
lactobezoar (lak′to-be′zor)

A bezoar attributed to enriched calcium or casein content in some formulas prepared for premature infants. [lacto- + bezoar]

lactobutyrometer
lactobutyrometer (lak′to-bu-ti-rom′e-ter)

A type of lactocrit. [lacto- + G. boutyron, butter, + metron, measure]

lactocele
lactocele (lak′to-sel)

SYN: galactocele. [lacto- + G. kele, tumor]

lactochrome
lactochrome (lak′to-krom)

SYN: lactoflavin (1) .

lactocrit
lactocrit (lak′to-krit)

An instrument used to estimate the amount of butterfat in milk. [lacto- + G. krino, to separate]

lactodensimeter
lactodensimeter (lak′to-den-sim′e-ter)

A type of galactometer. [lacto- + L. densus, thick, + G. metron, measure]

lactoferrin
lactoferrin (lak′to-far-in)

A transferrin found in the milk of several mammalian species and thought to be involved in the transport of iron to erythrocytes; relatively high concentrations are found in human milk.

lactoflavin
lactoflavin (lak′to-fla-vin)

1. The flavin in milk. SYN: lactochrome. 2. SYN: riboflavin.

lactogen
lactogen (lak′to-jen)

An agent that stimulates milk production or secretion. [lacto- + G. -gen, producing]
human placental l. (HPL) l. isolated from human placentas and structurally similar to somatotropin; its biologic activity weakly mimics that of somatotropin and prolactin; secreted into maternal circulation; a deficiency of HPL during pregnancy leads to children having abnormal intrauterine and postnatal growth. SYN: choriomammotropin, chorionic “growth hormone-prolactin”, human chorionic somatomammotropic hormone, human chorionic somatomammotropin, placenta protein, placental growth hormone, purified placental protein.

lactogenesis
lactogenesis (lak-to-jen′e-sis)

Milk production. [lacto- + G. genesis, production]

lactogenic
lactogenic (lak-to-jen′ik)

Pertaining to lactogenesis.

lactoglobulin
lactoglobulin (lak-to-glob′u-lin)

The globulin present in milk, making up 50–60% of bovine whey protein.

lactometer
lactometer (lak-tom′e-ter)

SYN: galactometer. [lacto- + G. metron, measure]

lactonase
lactonase (lak′to-nas)

SYN: gluconolactonase.

lactone
lactone (lak′ton)

An intramolecular organic anhydride formed from a hydroxyacid by the loss of water between a hydroxyl and a –COOH group; a cyclic ester.

lactoperoxidase
lactoperoxidase (lak′to-per-oks′i-das)

A peroxidase obtained from milk. It also catalyzes the oxidation of iodide to iodine.

lactoprotein
lactoprotein (lak-to-pro′ten)

Any protein normally present in milk.

lactorrhea
lactorrhea (lak-to-re′a)

SYN: galactorrhea. [lacto- + G. rhoia, a flow]

lactoscope
lactoscope (lak′to-skop)

SYN: galactoscope. [lacto- + G. skopeo, to view]

lactose
lactose (lak′tos)

A disaccharide present in mammalian milk, occurring naturally as α- and β-l.; obtained from cow's milk and used in modified milk preparation, in food for infants and convalescents, and in pharmaceutical preparations; large doses act as an osmotic diuretic and as a laxative. Human milk contains 6.7% l.. SYN: milk sugar, saccharum lactis.
l. synthase the enzyme responsible for the synthesis of l., catalyzing the reaction between UDP-galactose and d-glucose to l. and UDP.

lactosuria
lactosuria (lak′to-soo′re-a)

Excretion of lactose (milk sugar) in the urine; a common finding during pregnancy and lactation, and in newborns, especially premature babies. [lactose + G. ouron, urine, + -ia]

lactotherapy
lactotherapy (lak-to-thar′a-pe)

SYN: galactotherapy.

lactotrophic
lactotrophic

Older term for prolactin-producing.

lactotropin
lactotropin (lak-to-tro′pin)

SYN: prolactin.

lactovegetarian
lactovegetarian (lak′to-vej-e-ta′re-an)

1. One who lives on a mixed diet of milk and milk products, eggs, and vegetables, but eschews meat. 2. A vegetarian who consumes milk and dairy products but not eggs or meats or seafood.

lactoylglutathione lyase
lactoylglutathione lyase (lak′to-il-gloo-ta-thi′on)

Glyoxalase I;a lyase cleaving S-d-lactoylglutathione to glutathione and methylglyoxal. SYN: aldoketomutase, ketone-aldehyde mutase, methylglyoxalase.

lactulose
lactulose (lak′too-los)

A synthetic disaccharide used to treat hepatic encephalopathy and chronic constipation.

lacuna
lacuna, pl .lacunae (la-koo′na, -koo′ne)

1. [TA] A small space, cavity, or depression. 2. A gap or defect. 3. An abnormal space between strata or between the cellular elements of the epidermis. 4. SYN: corneal space. [L. a pit, dim. of lacus, a hollow, a lake]
cartilage l. a cavity within the matrix of cartilage, occupied by a chondrocyte. SYN: cartilage space.
cerebral l. a small circumscribed loss of brain tissue caused by occlusion of one of the small penetrating arteries. SYN: l. cerebri.
l. cerebri SYN: cerebral l..
Howship lacunae tiny depressions, pits, or irregular grooves in bone that is being resorbed by osteoclasts. SYN: resorption lacunae.
intervillous l. one of the blood spaces in the placenta into which the chorionic villi project.
lateral lacunae [TA] SYN: lateral lacunae of superior sagittal sinus.
lacunae laterales [TA] SYN: lateral lacunae of superior sagittal sinus.
lateral lacunae of superior sagittal sinus [TA] lateral expansions of the superior sagittal sinus of the dura mater, often increasing in width with advancing age until, in the very old, they may extend two cm lateral to the midline; the endothelium-lined lumens of the lacunae are usually reduced to a spongelike labyrinth by numerous arachnoid granulations and dural trabeculae. SYN: lacunae laterales [TA] , lateral lacunae [TA] , lateral lakes, lateral venous lacunae, parasinoidal sinuses.
lateral venous lacunae SYN: lateral lacunae of superior sagittal sinus.
l. magna a recess on the roof of the fossa navicularis of the penis, formed by a fold of mucous membrane, the valve of the navicular fossa.
Morgagni l. SYN: urethral l..
muscular l. SYN: muscular space of retroinguinal compartment.
l. musculorum SYN: muscular space of retroinguinal compartment.
l. musculorum retroinguinalis SYN: muscular space of retroinguinal compartment.
osseous l. a cavity in bony tissue occupied by an osteocyte.
pharyngeal l. a depression near the pharyngeal opening of the pharyngotympanic (auditory) tube. SYN: l. pharyngis.
l. pharyngis SYN: pharyngeal l..
resorption lacunae SYN: Howship lacunae.
trophoblastic l. one of the spaces in the early syncytiotrophoblastic layer of the chorion before the formation of villi; in human embryos maternal blood enters these spaces by the 10th day; with the differentiation of the chorionic villi they become intervillous spaces, sometimes called intervillous lacunae.
urethral l. [TA] one of a number of little recesses in the mucous membrane of the spongy urethra into which empty the ducts of the urethral glands. SYN: l. urethralis [TA] , Morgagni l..
l. urethralis, pl .lacunae urethrales [TA] SYN: urethral l..
vascular l. SYN: vascular space of retroinguinal compartment.
l. vasorum SYN: vascular space of retroinguinal compartment.
l. vasorum retroinguinalis [TA] SYN: vascular space of retroinguinal compartment.

lacunar
lacunar (la-koo′nar)

Relating to a lacuna.

lacunule
lacunule (la-koo′nool)

A very small lacuna. [Mod. L. lacunula, dim. of L. lacuna]

lacus
lacus, pl .lacus (la′kus) [TA]

SYN: lake (1) . [L. lake]
l. lacrimalis [TA] SYN: lacrimal lake.
l. seminalis SYN: seminal lake.

LAD
LAD

Abbreviation for leukocyte adhesion deficiency.

Ladd
Ladd

William E., U.S. pediatric surgeon, 1880–1967. See L. band, L. operation.

Ladd-Franklin
Ladd-Franklin

Christine, U.S. psychologist, 1847–1930. See Ladd-Franklin theory.

Laelaps echidninus
Laelaps echidninus (le′laps e-kid-ni′nus)

The spiny rat mite, a common worldwide ectoparasite of the wild Norway rat and occasionally found on the house mouse, cotton rat, and other rodents; it is the natural vector of Hepatozoon muris and can transmit the agent of tularemia experimentally. Junin virus has been isolated from this species in South America.

Laënnec
Laënnec

René T.H., French physician, 1781–1826. See L. cirrhosis, L. pearls, under pearl.

laetrile
laetrile (la′e-tril)

An allegedly antineoplastic drug consisting chiefly of amygdalin derived from apricot pits; its antitumor effect is unproven.

laev- laev-

See levo-.

Lafora
Lafora

Gonzalo Rodriguez, Spanish neurologist, 1887–1971. See L. body, L. body disease, L. disease.

lag
lag

1. To move or progress more slowly than normal; to fall behind. 2. The act or condition of falling behind. 3. The time interval between a change in one variable and a consequent change in another variable.
anaphase l. slowing or arrest in the normal migration of chromosomes during anaphase, resulting in such chromosomes being excluded from one of the daughter cells.
homeostatic l. the interval in a homeostatic process between a change of the trait controlled and the appropriate response, due to afferent, efferent, and central components. The l. may be a pure random variable, e.g., the waiting time of an exponential process or the sum of several such processes taking any value greater than zero but with a mean considerably greater than zero; sometimes it may be deterministic or almost so and with a minimum sharply defined and greater than zero for anatomical reasons. For instance, the partial pressures of oxygen and carbon dioxide are controlled in the lungs but based on afferent information obtained from the carotid body that is already dated because of the circulation time of ten seconds or so between the two sites.

lagena
lagena, pl .lagenae (la-je′na, -je-ne)

1. SYN: cupular cecum of the cochlear duct. 2. One of the three parts of the membranous labyrinth of the inner ear of lower vertebrates; in mammals, the l. becomes the cochlea. [L. flask]

lagging
lagging

Retarded or diminished ventilatory movement of the affected side of the chest due to pleural disease with muscle splinting or collapse of a lung.

lagomorph
lagomorph (la′go-morf)

A member of the order Lagomorpha.

Lagomorpha
Lagomorpha (la-go-mor′fa)

An order of herbivorous mammals (class Eutheria) resembling rodents (order Rodentia) but having two pairs of upper incisors one behind the other; it includes the rabbits, hares, and pikas. [G. lagos, hare, + morphe, form]

lagophthalmia
lagophthalmia (lag-of-thal′me-a)

See lagophthalmos.

lagophthalmos
lagophthalmos, lagophthalmia (lag-of-thal′mos, lag-of-thal′me-a)

A condition in which a complete closure of the eyelids over the eyeball is difficult or impossible. [G. lagos, hare + ophthalmos, eye]

Lagrange
Lagrange

Pierre F., French ophthalmologist, 1857–1928.

Lahey
Lahey

Frank H., U.S. surgeon, 1880–1935. See L. forceps.

LAK
LAK

Abbreviation for lymphokine activated killer cells.

lake
lake (lak) [TA]

1. A small collection of fluid. SYN: lacus [TA] . 2. To cause blood plasma to become red as a result of the release of hemoglobin from the erythrocytes, as when the latter are suspended in water. SEE ALSO: lacuna. [A.S. lacu, fr. L. lacus, l.]
capillary l. the total mass of blood contained in capillary vessels.
lacrimal l. [TA] the small cisternlike area of the conjunctiva at the medial angle of the eye, in which the tears collect after bathing the anterior surface of the eyeball and the conjunctival sac. SYN: lacus lacrimalis [TA] , lacrimal bay.
lateral lakes SYN: lateral lacunae of superior sagittal sinus, under lacuna.
seminal l. the vault of the vagina after insemination. SYN: lacus seminalis.
subchorial l. SYN: subchorial space.
venous lakes 1. blue-purple, thin-walled, dilated blood vessels that blanch on pressure, found commonly in the ears and less often on the lips and on the face and neck of elderly sun-damaged men; 2. discontinuous venous cavities or channels; Cf.:marginal sinuses of placenta, under sinus. 3. in skull radiography, round to oval radiolucent foci in the frontal or parietal bones caused by dilated diploic venous channels.

Laki-Lorand factor
Laki-Lorand factor

See under factor.

laky
laky (la′ke)

Pertaining to the transparent bright red appearance of blood serum or plasma, developing as a result of hemoglobin being released from destroyed red blood cells.

laliatry
laliatry (la-li′a-tre)

The study and treatment of speech disorders. [G. lalia, speech, chatter, + iatria, cure]

laliophobia
laliophobia (lal′e-o-fo′be-a)

Morbid fear of speaking or stuttering. [G. lalia, speech, + phobos, fear]

Lallemand
Lallemand

Claude F., French surgeon, 1790–1853. See L. bodies, under body, Trousseau-L. bodies, under body.

lalling
lalling (lal′ing)

A form of stammering in which the speech is almost unintelligible. [G. laleo, to chatter]

Lallouette
Lallouette

Pierre, French physician, 1711–1792. See L. pyramid.

lalochezia
lalochezia (lal-o-ke′ze-a)

Emotional discharge gained by uttering indecent or filthy words. [G. lalia, speech, + chezo, to relieve oneself]

lalognosis
lalognosis (lal′og-no′sis)

Understanding and knowledge of speech. [G. lalia, speech, + gnosis, knowledge]

laloplegia
laloplegia (la-lo-ple′je-a)

Paralysis of the muscles concerned in the mechanism of speech. [G. lalia, speech, + plege, a stroke]

Lamarck
Lamarck

Jean-Baptiste P.A., French botanist, zoologist, and biologic philosopher, 1744–1829. See lamarckian theory.

Lamaze
Lamaze

Fernand, French obstetrician, 1890–1957. See L. method.

LAMB
LAMB

Acronym for lentigines, atrial myxoma, mucocutaneous myxomas, and blue nevi. See L. syndrome.

Lam B
Lam B

Outer membrane protein of Gram-negative bacteria.

lambda
lambda (lam′da)

1. The 11th letter of the Greek alphabet, &l.;. 2. The craniometric point at the junction of the sagittal and lambdoid sutures.

lambdacism
lambdacism (lam′da-sizm)

1. Mispronunciation or disarticulation of the letter l. 2. Substitution of the letter l for the letter r. [G. lambda, the letter L]

lambdoid
lambdoid (lam′doyd)

Resembling the Greek letter lambda (λ), as does the l. suture. [lambda + G. eidos, resemblance]

Lambert
Lambert

Edward H., U.S. physician, *1915. See L.-Eaton syndrome, Eaton-L. syndrome.

lambert
lambert (lam′bert)

A unit of brightness; the brightness of a perfectly diffusing surface emitting or reflecting a total luminous flux of 1 lumen/sq cm of surface. [J.H. L., German physicist and mathematician, 1728–1777]

Lamblia intestinalis
Lamblia intestinalis (lam′ble-a in-tes-ti-na′lis)

Old term for Giardia lamblia, still frequently used, especially by protozoologists in the former Soviet Union.

lambliasis
lambliasis (lam-bli′a-sis)

SYN: giardiasis.

lambo lambo
lambo lambo (lam′bo-lam′bo)

SYN: tropical pyomyositis.

Lambrinudi
Lambrinudi

Constantine, British orthopedic surgeon, 1890–1943. See L. operation.

lamella
lamella, pl .lamellae (la-mel′a, -mel′e) [TA]

1. [TA] A thin sheet or layer (such as occurs in compact bone) or sublayer. 2. A preparation in the form of a medicated gelatin disk, used as a means of making local applications to the conjunctiva in place of solutions. SYN: discus [TA] , disk (2) [TA] . [L. dim. of lamina, plate, leaf]
annulate lamellae several pairs of parallel, smooth membranes, each pair containing regularly spaced pores resembling those of the nuclear envelope; they occur in germ cells, embryonic cells, and neoplastic cells.
articular l. the compact layer of bone on its articular surface that is firmly attached to the overlying articular cartilage.
l. of bone a concentric, circumferential, or interstitial l..
circumferential l. a bony l. that encircles the outer or inner surface of a bone.
concentric l. one of the concentric tubular layers of bone surrounding the central canal in an osteon. SYN: haversian l..
cornoid l. a narrow vertical column of parakeratosis in the epidermal stratum corneum; characteristic of porokeratosis.
elastic l. a thin sheet or membrane composed of elastic fibers; distinguished from elastic membrane, which usually refers to a condensed mass of fibers, as in an artery, whereas an elastic l. may be a looser elastic layer such as found in a vein or the respiratory tract.
enamel l. an organic defect in enamel; a thin, leaflike structure that extends from the enamel surface toward the dentinoenamel junction.
glandulopreputial l. a layer of embryonic epithelial tissue that gives rise to the prepuce.
ground l. SYN: interstitial l..
haversian l. SYN: concentric l..
intermediate l. SYN: interstitial l..
interstitial l. one of the lamellae of partially resorbed osteons occurring between newer, complete osteons. SYN: ground l., intermediary system, intermediate l..
triangular l. SYN: tela choroidea of third ventricle.
l. tympanica (laminae spiralis ossei) [TA] SYN: tympanic l. (of osseous spiral lamina).
tympanic l. (of osseous spiral lamina) [TA] the thinner of two plates of bone, incompletely separated from each other by canals for peripheral fibers from the spiral (cochlear) ganglion, that together comprise the osseous spiral lamina; this plate lies on the side of the scala tympani, forming a portion of its wall. SYN: l. tympanica (laminae spiralis ossei) [TA] .
l. vestibularis (laminae spiralis ossei) [TA] SYN: vestibular l. (of osseous spiral lamina).
vestibular l. (of osseous spiral lamina) [TA] the thicker of two plates of bone, incompletely separated from each other by canals for peripheral fibers from the spiral (cochlear) ganglion, that together comprise the osseous spiral lamina; this plate lies on the side of the scala vestibuli; a thickening of the periosteum, the spiral limbus, is attached to the vestibular l. within the cochlear duct. SYN: l. vestibularis (laminae spiralis ossei) [TA] .
vitreous l. SYN: lamina basalis choroideae.

lamellar
lamellar (lam′e-lar, la-mel′ar)

1. Arranged in thin plates or scales. SYN: lamellate, lamellated. 2. Relating to lamellae.

lamellate
lamellate, lamellated (lam′e-lat, -ed)

SYN: lamellar (1) .

lamellipodium
lamellipodium, pl .lamellipodia (la-mel-i-po′de-um, -a)

A cytoplasmic veil produced on all sides of migrating polymorphonuclear leukocytes.

lamina
lamina, pl .laminae (lam′i-na, lam′i-ne) [TA]

SYN: plate (1) . SEE ALSO: layer, stratum. [L]
l. affixa [TA] that part of the medial ependymal wall of the lateral ventricle of the embryonic brain that in later development becomes adherent to the superior surface of the thalamus and thus comes to form the floor of the central part of the lateral ventricle; it covers the thalamostriate and choroidal veins.
l. alaris SYN: alar l. of neural tube.
alar l. of neural tube the dorsal division of the lateral walls of the neural tube in the embryo; it gives rise to neurons relaying afferent impulses to higher centers; in the adult such neurons compose the sensory nuclei of the spinal cord and brainstem. SYN: alar plate of neural tube, dorsolateral plate of neural tube, l. alaris, l. dorsalis, wing plate.
laminae albae cerebelli layers of white substance seen on section of the cerebellum. SYN: laminae medullares cerebelli.
l. anterior fasciae thoracolumbalis [TA] SYN: anterior layer of thoracolumbar fascia.
anterior limiting l. [TA] the periphery of the cornea marking the termination of Descemet membrane and the anterior border of the trabecular meshwork; an important landmark in gonioscopy. SYN: l. limitans anterior [TA] , anterior limiting ring, Schwalbe ring.
l. anterior vaginae musculi recti abdominis SYN: anterior layer of rectus sheath.
l. arcus vertebrae [TA] SYN: l. of vertebral arch.
basal l. 1. an amorphous extracellular layer applied to the basal surface of epithelium and also investing muscle cells, fat cells, and Schwann cells; thought to be a selective filter and to serve both structural and morphogenetic functions. It is composed of a 20–100 nm network of file filaments called the l. densa which appears dense in the electron microscope, and on either side of this layer is a less dense layer called the l. rarae; SEE ALSO: basement membrane, l. densa. 2. SYN: l. densa.
basal l. of choroid [TA] SYN: l. basalis choroideae.
basal l. of ciliary body [TA] the inner layer of the ciliary body, continuous with the basal layer of the choroid and supporting the pigment epithelium of the ciliary retina. SYN: l. basilaris corporis ciliaris [TA] , basal layer of ciliary body, l. basalis corporis ciliaris.
basal l. of cochlear duct [TA] the membrane extending from the bony spiral membrane to the basilar crest of the cochlea; it forms the greater part of the floor of the cochlear duct separating the latter from the scala tympani and it supports the organ of Corti. SYN: l. basilaris ductus cochlearis [TA] , basilar l., basilar membrane of cochlear duct, l. basilaris cochleae, membrana basilaris.
l. basalis SYN: basal l. of neural tube.
l. basalis choroideae [TA] the transparent, nearly structureless inner layer of the choroid in contact with the pigmented layer of the retina. SYN: basal l. of choroid [TA] , basal layer of choroid [TA] , Bruch membrane, Henle membrane, l. vitrea, vitreous lamella, vitreous membrane (3) .
l. basalis corporis ciliaris SYN: basal l. of ciliary body.
basal l. of neural tube the ventral division of the lateral walls of the neural tube in the embryo; it contains neuroblasts giving rise to somatic and visceral motor neurons. SYN: basal plate of neural tube, l. basalis, l. ventralis, ventral plate of neural tube.
basal l. of semicircular duct SYN: basal membrane of semicircular duct.
basement l. SYN: basement membrane.
basilar l. SYN: basal l. of cochlear duct.
l. basilaris cochleae SYN: basal l. of cochlear duct.
l. basilaris corporis ciliaris [TA] SYN: basal l. of ciliary body.
l. basilaris ductus cochlearis [TA] SYN: basal l. of cochlear duct.
boundary l. a basement membrane-like structure that invests muscle cells, fat cells, and Schwann cells. SEE ALSO: basement membrane, basal l..
capillary l. of choroid [TA] the internal or deep portion of the choroidea of the eye, composed of a very close capillary network. SYN: l. choroidocapillaris [TA] , choriocapillaris, choriocapillary layer, entochoroidea, l. choriocapillaris, membrana choriocapillaris, Ruysch membrane.
l. cartilaginis cricoideae [TA] SYN: l. of cricoid cartilage.
l. cartilaginis thyroideae [TA] SYN: l. of thyroid cartilage.
l. choriocapillaris SYN: capillary l. of choroid.
l. choroidea SYN: epithelial l..
l. choroidea epithelialis SYN: epithelial l..
l. choroidocapillaris [TA] SYN: capillary l. of choroid.
l. cinerea SYN: l. terminalis of cerebrum.
l. cribrosa ossis ethmoidalis [TA] SYN: cribriform plate of ethmoid bone.
l. cribrosa of sclera [TA] the portion of the sclera through which pass the fibers of the optic nerve. SYN: l. cribrosa sclerae [TA] , cribrous l., perforated layer of sclera.
l. cribrosa sclerae [TA] SYN: l. cribrosa of sclera.
cribrous l. SYN: l. cribrosa of sclera.
l. of cricoid cartilage [TA] a quadrate plate forming the posterior part of the cricoid cartilage. It resembles the shield of a signet ring, the arch of the cricoid representing the remainder of the ring. SYN: l. cartilaginis cricoideae [TA] .
deep l. SYN: deep layer.
l. densa 1. the electron-dense layer of the basal l. as seen in the electron microscope; SEE ALSO: basement membrane. 2. the extraordinarily thick basal l. of the renal glomerulus. SYN: basal l. (2) .
dental l. SYN: dental ledge.
l. dentata SYN: vestibular lip of spiral limbus.
dentogingival l. SYN: dental ledge.
l. dorsalis SYN: alar l. of neural tube.
l. dura the hard layer lining the dental alveoli.
l. elastica anterior SYN: anterior limiting layer of cornea.
l. elastica posterior SYN: posterior limiting l. of cornea.
elastic laminae of arteries 1) external: the layer of elastic connective tissue lying immediately outside the smooth muscle of the tunica media; 2) internal: a fenestrated layer of elastic tissue of the tunica intima. SYN: elastic layers of arteries, Henle fenestrated elastic membrane.
l. epiphysialis [TA] SYN: epiphysial plate.
episcleral l. SYN: episcleral layer of fibrous layer of eyeball.
l. episcleralis [TA] SYN: episcleral layer of fibrous layer of eyeball.
epithelial l. the layer of modified ependymal cells that forms the inner layer of the tela choroidea, facing the ventricle. SYN: epithelial choroid layer, l. choroidea epithelialis, l. choroidea, l. epithelialis.
l. epithelialis SYN: epithelial l..
l. externa calvaria [TA] SYN: external table of calvaria.
l. externa cranii SYN: external table of calvaria.
external medullary l. [TA] See medullary laminae of thalamus.
l. fibrocartilaginea interpubica SYN: interpubic disk.
l. fibroreticularis a layer of the basement membrane in continuity with associated connective tissue; it is often discontinuous and may be lacking entirely in some cases.
l. fusca of sclera SYN: suprachoroid l. of sclera.
l. fusca sclerae [TA] SYN: suprachoroid l. of sclera.
hepatic laminae the plates of liver cells that radiate from the center of the liver lobule.
l. horizontalis ossis palatini [TA] SYN: horizontal plate of palatine bone.
l. interna calvariae [TA] SYN: internal table of calvaria.
l. interna cranii SYN: internal table of calvaria.
internal medullary l. [TA] See medullary laminae of thalamus.
l. interna ossium cranii SYN: vitreous table.
iridopupillary l. embryonic precursor of the anterior stroma of the iris that forms the inner (posterior or deep) wall of the primary anterior chamber of the eye. Its central portion becomes attenuated as the pupillary membrane (membrana pupillaris [NA]).
labiogingival l. a band of ectodermal epithelial cells growing into the mesenchyme of the embryonic jaws between the developing lip and the growing gingival elevation; it later opens to form the labiogingival groove.
lateral l. of cartilage of pharyngotympanic (auditory) tube [TA] the narrow lateral portion of the cartilaginous part of the pharyngotympanic (auditory) tube. SYN: l. lateralis cartilaginis tubae auditivae [TA] , l. lateralis cartilaginis tubae auditoriae&star, lateral cartilaginous plate, lateral plate of cartilaginous auditory tube.
l. lateralis cartilaginis tubae auditivae [TA] SYN: lateral l. of cartilage of pharyngotympanic (auditory) tube.
l. lateralis cartilaginis tubae auditoriae lateral l. of cartilage of pharyngotympanic (auditory) tube.
l. lateralis processus pterygoidei [TA] SYN: lateral pterygoid plate.
lateral medullary l. [TA] of lentiform nucleus a thin, sharply defined layer of fibers separating the putamen from the globus pallidus. SYN: l. medullaris lateralis nuclei lentiformis [TA] .
l. of lens one of a series of concentric layers composed of the lens fibers that make up the substance of the lens.
l. limitans anterior [TA] SYN: anterior limiting l..
l. limitans anterior corneae SYN: anterior limiting layer of cornea.
l. limitans posterior corneae SYN: posterior limiting l. of cornea.
l. lucida the lightly staining layer of the basement membrane in contact with the plasmalemma of epithelial cells or other cells having an investment of basement membrane.
medial l. of cartilage of pharyngotympanic (auditory) tube [TA] the broad medial portion of the cartilaginous part of the pharyngotympanic (auditory) tube. SYN: l. medialis cartilaginis tubae auditivae [TA] , l. medialis cartilaginis tubae auditoriae&star, medial cartilaginous plate, medial plate of cartilaginous auditory tube.
l. medialis cartilaginis tubae auditivae [TA] SYN: medial l. of cartilage of pharyngotympanic (auditory) tube.
l. medialis cartilaginis tubae auditoriae medial l. of cartilage of pharyngotympanic (auditory) tube, medial l. of cartilage of pharyngotympanic (auditory) tube.
l. medialis processus pterygoidei [TA] SYN: medial pterygoid plate.
medial medullary l. [TA] of lentiform nucleus a fiber layer separating the medial and lateral segments of the globus pallidus. SYN: l. medullaris medialis nuclei lentiformis [TA] .
laminae medullares cerebelli SYN: laminae albae cerebelli.
laminae medullares thalami SYN: medullary laminae of thalamus.
l. medullaris lateralis [TA] See medullary laminae of thalamus.
l. medullaris lateralis nuclei lentiformis [TA] SYN: lateral medullary l. [TA] of lentiform nucleus.
l. medullaris medialis [TA] See medullary laminae of thalamus.
l. medullaris medialis nuclei lentiformis [TA] SYN: medial medullary l. [TA] of lentiform nucleus.
medullary laminae of thalamus layers of myelinated fibers that appear on transverse sections of the thalamus; the l. medullaris lateralis [TA] (external medullary l. [TA]) marks the ventral and lateral borders of the thalamus and delimits it from the subthalamus and reticular nucleus of thalamus; the l. medullaris medialis [TA] (internal medullary l. [TA]) is interposed between the mediodorsal and ventral nuclei of the thalamus and encloses the intralaminar nuclei (centromedian, paracentral, and central lateral nuclei). SYN: laminae medullares thalami, medullary layers of thalamus.
l. membranacea cartilaginis tubae auditivae [TA] SYN: membranous l. of cartilage of pharyngotympanic (auditory) plate.
l. membranacea cartilaginis tubae auditoriae membranous l. of cartilage of pharyngotympanic (auditory) plate.
membranous l. of cartilage of pharyngotympanic (auditory) plate [TA] the connective tissue membrane that, with the lateral and medial laminae, completes the lateral and inferior walls of the cartilaginous part of the pharyngotympanic (auditory) tube. SYN: l. membranacea cartilaginis tubae auditivae [TA] , l. membranacea cartilaginis tubae auditoriae&star, membranous layer.
l. of mesencephalic tectum the roofplate of the mesencephalon formed by the quadrigeminal bodies. SYN: l. tecti [TA] , tectal plate [TA] , tectum mesencephali [TA] , l. quadrigemina, quadrigeminal l., quadrigeminal plate, tectum of midbrain.
l. modioli cochleae [TA] SYN: l. of modiolus of cochlea.
l. of modiolus of cochlea [TA] a bony plate, the continuation of the modiolus and of the septum between the convolutions of the spiral canal of the cochlea extending upward toward the cupola, forming with the hamulus the helicotrema. SYN: l. modioli cochleae [TA] , plate of modiolus.
l. molecularis corticis cerebri [TA] SYN: molecular layer of cerebral cortex.
l. muscularis mucosae SYN: muscularis mucosae.
nuclear l. a protein-rich layer lining the inner surface of the nuclear membrane in interphase cells.
orbital l. of ethmoid bone SYN: orbital plate of ethmoid bone.
l. orbitalis ossis ethmoidalis [TA] SYN: orbital plate of ethmoid bone.
osseous spiral l. [TA] a double plate of bone winding spirally around the modiolus dividing the spiral canal of the cochlea incompletely into two, scala tympani and scala vestibuli; between the two plates of this l., the fibers of the cochlear nerve reach the spiral organ (of Corti). SYN: l. spiralis ossea [TA] , spiral plate.
l. papyracea SYN: orbital plate of ethmoid bone.
l. parietalis [TA] SYN: parietal layer.
l. parietalis pericardii serosi [TA] SYN: parietal layer of serous pericardium.
l. parietalis tunicae vaginalis testis [TA] SYN: parietal layer of tunica vaginalis of testis.
periclaustral l. SYN: external capsule.
l. perpendicularis [TA] SYN: perpendicular plate.
l. perpendicularis ossis ethmoidalis [TA] SYN: perpendicular plate of ethmoid bone.
l. perpendicularis ossis palatini [TA] SYN: perpendicular plate of palatine bone.
posterior limiting l. of cornea [TA] a transparent homogeneous acellular layer between the substantia propria and the endothelial layer of the cornea; considered to be a highly developed basement membrane. SYN: Descemet membrane, Duddell membrane, entocornea, hyaloid membrane, l. elastica posterior, l. limitans posterior corneae, membrana hyaloidea, membrana vitrea, posterior elastic layer, posterior limiting layer of cornea, tunica vitrea, vitreous membrane (1) .
l. posterior vaginae musculi recti abdominis [TA] SYN: posterior layer of rectus sheath.
l. pretrachealis fasciae cervicalis [TA] SYN: pretracheal layer of cervical fascia.
l. prevertebralis fasciae cervicalis [TA] SYN: prevertebral layer of cervical fascia.
primary dental l. SYN: dental ledge.
l. profunda [TA] SYN: deep layer.
l. profunda fasciae temporalis [TA] SYN: deep layer of temporal fascia.
l. profunda fasciae thoracolumbalis anterior layer of thoracolumbar fascia.
l. profunda musculi levatoris palpebrae superioris SYN: deep layer of levator palpebrae superioris.
l. propria [TA] the layer of connective tissue underlying the epithelium of a mucous membrane. SYN: l. propria mucosae.
l. propria mucosae SYN: l. propria.
pterygoid laminae lateral pterygoid plate, medial pterygoid plate.
l. quadrigemina SYN: l. of mesencephalic tectum.
quadrigeminal l. SYN: l. of mesencephalic tectum.
l. rara the relatively electron-lucent layer on either side of the l. densa of the basement membrane.
reticular l. 1. a major component of the basement membrane, as seen by light microscopy; it consists largely of reticular fibers and ground substance. 2. the connective tissue plate in which the hair-bearing ends of the auditory sensory cells of the organ of Corti are embedded.
retrorectal l. of endopelvic fascia SYN: presacral fascia.
retrorectal l. of hypogastric sheath SYN: presacral fascia.
l. retrorectalis fasciae endopelvicae SYN: presacral fascia.
l. of Rexed a division of the gray matter of the spinal cord into nine laminae (I–IX) and a gray area around the central canal (area X) based on cytoarchitectural features; the dorsal (posterior) horn is composed of laminae I–VI, the intermediate zone of l. VII, and the ventral horn of laminae VIII and IX; general correlation of laminae with some of the major nuclei: I, posteromarginal nucleus; II, substantia gelatinosa; III and IV, nucleus proprius cornu dorsalis; V and VI, sometimes described as containing the spinal reticular formation; VII, Clarke nucleus, intermediolateral cell column; VIII, commissural nuclei, interneurons; IX, motor nuclei of ventral horn.
rostral l. a whitish line appearing on perfectly median sections of the brain as a thin bridge connecting the rostrum of the corpus callosum with the l. terminalis; the rostral l. contains no commissural fibers; instead, it corresponds to the line along which the pia mater reflects from the medial surface of one hemisphere to that of the other. SYN: l. rostralis, rostral layer, taeniola corporis callosi.
l. rostralis SYN: rostral l..
secondary spiral l. [TA] a ridge on the outer wall of the first turn of the cochlea opposite the spiral l.. SYN: l. spiralis secundaria [TA] , secondary spiral plate.
l. septi pellucidi SYN: l. of septum pellucidum.
l. of septum pellucidum one of the two thin layers of the transparent septum, which extend from the corpus callosum to the fornix; often separated from each other by a space, the cavity of septum pellucidum. SYN: l. septi pellucidi.
spinal l. II gelatinous substance.
l. spinalis II gelatinous substance.
l. spiralis ossea [TA] SYN: osseous spiral l..
l. spiralis secundaria [TA] SYN: secondary spiral l..
successional l. an ectodermal bud on the labial side of the dental l. that develops into a permanent tooth.
superficial l. SYN: superficial layer.
l. superficialis [TA] SYN: superficial layer.
l. superficialis fasciae cervicalis [TA] SYN: investing layer of cervical fascia.
l. superficialis fasciae temporalis [TA] SYN: superficial layer of temporal fascia.
l. superficialis musculi levatoris palpebrae superioris SYN: superficial layer of the levator palpebrae superioris.
suprachoroid l. of sclera [TA] an exceedingly delicate layer of loose, pigmented connective tissue between the inner surface of the sclera and the outer surface of the choroid, connecting them; formerly, the l. fusca and suprachoroid l. were considered as two adjacent layers. SYN: l. fusca sclerae [TA] , brown layer, ectochoroidea, l. fusca of sclera, membrana fusca, suprachoroidea.
l. supraneuroporica that part of the choroid membrane of the third ventricle that forms the roof of the foramen of Monro.
l. tecti [TA] SYN: l. of mesencephalic tectum.
l. terminalis [TA] SYN: l. terminalis of cerebrum.
l. terminalis of cerebrum [TA] a thin plate passing upward from the optic chiasm and forming the rostral boundary of the third ventricle; membrane closing the rostral neuropore. SYN: l. terminalis [TA] , l. cinerea, terminal plate, velum terminale.
l. of thyroid cartilage [TA] one of the paired (right and left) thin quadrilateral plates of the thyroid cartilage that are joined anteriorly and form an open angle posteriorly. SYN: l. cartilaginis thyroideae [TA] .
tragal l. [TA] a longitudinal curved plate of cartilage, the beginning of the cartilaginous portion of the external acoustic meatus. SYN: l. tragi [TA] , l. of tragus.
l. tragi [TA] SYN: tragal l..
l. of tragus SYN: tragal l..
vascular l. of choroid [TA] the external or superficial portion of the choroid of the eye containing the largest blood vessels. SYN: l. vasculosa choroideae [TA] , Haller vascular tissue, uvaeformis, vascular layer of choroid coat of eye, vascular layer.
l. vasculosa choroideae [TA] SYN: vascular l. of choroid.
l. ventralis SYN: basal l. of neural tube.
l. of vertebral arch [TA] the flattened posterior portion of the vertebral arch extending between the pedicles and the midline, forming the dorsal wall of the vertebral foramen, and from the midline junction of which the spinous process extends. SYN: l. arcus vertebrae [TA] , neurapophysis.
l. visceralis [TA] SYN: visceral layer.
l. visceralis pericardii SYN: visceral layer of serous pericardium.
l. visceralis tunicae vaginalis testis [TA] SYN: visceral layer of tunica vaginalis of testis.
l. vitrea SYN: l. basalis choroideae.

laminagram
laminagram (lam′i-na-gram)

An image made by laminagraphy (q.v.). SEE ALSO: tomography.

laminagraph
laminagraph (lam′i-na-graf)

A device for laminagraphy; a laminagram.

laminagraphy
laminagraphy, laminography (lami-nahg′ra-fe, lam-i-nog′-ra-fe)

Radiographic technique in which the images of tissues above and below the plane of interest are blurred out by reciprocal movement of the x-ray tube and film holder, to show a specific area more clearly. SEE ALSO: tomography. [lamina + G. graphe, a writing]

laminar
laminar (lam′i-nar)

1. Arranged in plates or laminae. SYN: laminated. 2. Relating to any lamina.

laminaria
laminaria (lam-i-na′re-a)

Sterile rod made of kelp (genus L.) which is hydrophilic, and, when placed in the cervical canal, absorbs moisture, swells, and gradually dilates the cervix. [L. lamina, a blade]

laminarin
laminarin (lam-i-nar′in)

An algal polysaccharide, made up chiefly of β-d-glucose residues, obtained from Laminaria species (family Laminariaceae); variable proportions of the glucose chains contain at the potential reducing end a molecule of mannitol that can be sulfated.
l. sulfate l. sulfated to varying degrees; two sulfate groups per glucose unit result in maximum stability and anticoagulant activity similar to that of heparin; l. with fewer sulfate groups has only antilipemic activity.

laminated
laminated (lam′i-nat-ed)

SYN: laminar (1) .

lamination
lamination (lam-i-na′shun)

1. An arrangement in the form of plates or laminae. 2. Embryotomy by removing the fetal head in slices.

laminectomy
laminectomy (lam′i-nek′to-me)

Excision of a vertebral lamina; commonly used to denote removal of the posterior arch. [L. lamina, layer, + G. ektome, excision]

laminin
laminin (lam′i-nin)

A large multimeric glycoprotein component of the basement membrane; particularly its unstained laminae; a major protein component of the laminae of the renal glomerulus.

laminitis
laminitis (lam-i-ni′tis)

Inflammation of any lamina.

laminography
laminography (lam-i-nog′-ra-fe)

See laminagraphy.

laminotomy
laminotomy (lam-′i-not′o-me)

Excision of a portion of a vertebral lamina in which the intervertebral foramen is enlarged by removal of a portion of the lamina. SYN: rachiotomy. [L. lamina, layer, + G. tome, incision]

lamins
lamins (lam′inz)

Fibrous network associated with the inner membranes of cell nuclei, composed of polypeptides of varying molecular weights (60,000–80,000) and classified as A, B, C, etc. on the basis of physical properties; the phosphorylation of l. is associated with mitosis.

lamotrigine
lamotrigine (la-mo′tri-jen)

New structural class of antiepileptics; an anticonvulsant which appears in preclinical studies to resemble phenytoin.

lamp
lamp (lamp)

Illuminating device; source of light. SEE ALSO: light.
annealing l. an alcohol l. with a soot-free flame used in dentistry to drive off the protective NH₃ gas coating from the surface of cohesive gold foil.
Edridge-Green l. a lantern used to test recognition of colored signals; it displays a single light with color filters in rotating disks that can be modified to simulate conditions of weather and atmosphere. This test for color blindness was officially adopted in Great Britain in 1915 in place of the Holmgren wool test, but is now seldom used.
heat l. a l. that emits infrared light and produces heat; used to apply topical heat to the skin.
mercury vapor l. a l. in which the electric arc is in an ionized mercury vapor atmosphere; it produces ultraviolet light that can be used therapeutically or in diagnostic photometry.
mignon l. a minute electric light used in various endoscopic instruments.
slit l. a combination of a microscope and a narrow beam of collimated light, used to examine the eye.
spirit l. a l., used mainly for heating in laboratory work, in which alcohol is burned.
tungsten arc l. a l. having highly compressed tungsten elements.
ultraviolet l. a l. that emits rays in the ultraviolet band of the spectrum. SEE ALSO: ultraviolet.
Wood l. an ultraviolet l. with a nickel oxide filter that only passes light with a maximal wavelength of about 3660 Å; used to detect by fluorescence hairs infected Microsporum audouinii, M. canis, var. distortum, or M. ferrugineum, producing greenish-yellow fluorescence.

Lamy
Lamy

Maurice, French physician, 1895–1975. See Maroteaux-L. syndrome.

lana
lana, gen. and pl. lanae (lan′a, lan′e)

SYN: wool. [L.]

lanatoside D
lanatoside D (la-nat′o-sid)

A digitalis glycoside from the leaves of Digitalis lanata, yielding the genin diginatigenin (12-hydroxygitoxigenin; 16-hydroxydigoxigenin).

lanatosides A, B, and C
lanatosides A, B, and C (la-nat′o-sidz)

Digilanides A, B, and C; the cardioactive precursor glycosides obtained from Digitalis lanata. Removal of the acetyl group yields desacetyllanatosides A, B, and C (purpurea glycosides A, B, and C, respectively); removal of the glucose from lanatosides A, B, and C yields acetyldigitoxin, acetylgitoxin, and acetyldigoxin, respectively; removal of glucose and the acetyl group yields digitoxin, gitoxin, and digoxin, respectively. SEE ALSO: purpurea glycosides A.

lance
lance (lans)

1. To incise a part, as an abscess or boil. 2. A lancet. [L. lancea, a slender spear]

Lancefield
Lancefield

Rebecca Craighill, U.S. bacteriologist, 1895–1981. See L. classification.

lancet
lancet (lan′set)

A surgical knife with a short, wide, sharp-pointed, two-edged blade. [Fr. lancette]
gum l. a l. used for incising the gum over the crown of an erupting tooth.
spring l. a l. with a handle containing a blade that is activated by a spring.
thumb l. a l. with short flat blade that folds back, when closed, between two plates of the handle.

lancinating
lancinating (lan′si-nat′ing)

Denoting a sharp cutting or tearing pain. [L. lancino, pp. -atus, to tear]

Lancisi
Lancisi

Giovanni M., Italian physician, 1654–1720. See L. sign, striae l., under stria.

Landau-Kleffner syndrome
Landau-Kleffner syndrome

See under syndrome.

Landouzy
Landouzy

Louis T.J., French neurologist, 1845–1917. See L.-Dejerine dystrophy, L.-Grasset law.

Landry
Landry

Jean B.O., French physician, 1826–1865. See L. paralysis, L. syndrome, L.-Guillain-Barré syndrome.

Landschutz tumor
Landschutz tumor

See under tumor.

Landsteiner
Landsteiner

Karl, Austrian-U.S. pathologist and Nobel laureate, 1868–1943. See L.-Donath test, Donath-L. cold autoantibody, Donath-L. phenomenon.

Landström
Landström

John, Swedish surgeon, 1869–1910. See L. muscle.

Landzert
Landzert

T., 19th century German anatomist. See L. fossa, Gruber-L. fossa.

Lane
Lane

Sir William Arbuthnot, English surgeon, 1856–1943. See L. band, L. disease.

Lang
Lang

Basil T., English ophthalmologist, 1880–1928.

Lange
Lange

Carl F.A., German biochemist, *1883. See L. solution, L. test.

Lange
Lange

Cornelia de. See under de L..

Langenbeck
Langenbeck

Bernhard R.K. von, German surgeon, 1810–1887. See L. triangle.

Langendorff
Langendorff

Oscar, German physiologist, 1853–1908. See L. method.

Lange-Nielsen
Lange-Nielsen

F., 20th century Norwegian cardiologist. See Jervell and Lange-Nielsen syndrome.

Langer
Langer

Carl (Ritter von Edenberg), Austrian anatomist, 1819–1887. See L. arch, L. lines, under line, L. muscle.

Langer
Langer

Leonard O., American physician. See L.-Saldino syndrome.

Langerhans
Langerhans

Paul, German anatomist, 1847–1888. See L. cells, under cell, L. granule, L. islands, under island, islets of L., under islet.

Langhans
Langhans

Theodor, German pathologist, 1839–1915. See L. cells, under cell, L.-type giant cells, under cell, L. layer, L. stria.

Langley
Langley

John N., English physiologist, 1852–1925. See L. granules, under granule.

Langmuir
Langmuir

Irving, U.S. chemist and Nobel laureate, 1881–1957. See L. trough.

language
language (lang′gwij)

The use of spoken, manual, written, and other symbols to express, represent, or receive communication. [L. lingua]
American Sign L. (ASL) the manual sign and gesture l. used by the deaf community in the United States. It is a l. distinct from English, with its own grammar and syntax, but no written form.
body l. 1. the expression of thoughts and feelings by means of nonverbal bodily movements, e.g., gestures, or via the symptoms of hysterical conversion; See kinesics. 2. communication by means of bodily signs.

laniary
laniary (lan′i-ar-e)

Adapted for tearing; in anatomy, sometimes applied to canine teeth, as l. teeth. [L. lanio, to tear to pieces]

lankamycin
lankamycin (lan′ka-mi-sin)

Macrolide antibiotic produced by Streptomyces violaceoniger from the soil of Sri Lanka.

Lannelongue
Lannelongue

Odilon M., French surgeon and pathologist, 1840–1911. See L. foramina, under foramen, L. ligaments, under ligament.

lanolin
lanolin (lan′o-lin)

SYN: adeps lanae. [L. lana, wool, + oleum, oil]
anhydrous l. l. that contains not more than 0.25% of water; used as a water-adsorbable ointment base.

lanosterol
lanosterol (lan-o′ster-ol)

A zoosterol synthesized from squalene and a precursor to cholesterol.

Lanterman
Lanterman

A.J., 19th century U.S. anatomist in Strasbourg. See L. incisures, under incisure, L. segments, under segment, Schmidt-L. clefts, under cleft, Schmidt-L. incisures, under incisure.

lanthanic
lanthanic (lan′tha-nik)

Rarely used term denoting a disease process that produces no symptoms or clinical evidence of illness. [G. lanthano, to lie hidden]

lanthanides
lanthanides (lan′tha-nidz)

Those elements with atomic numbers 57–71 that closely resemble one another chemically and were once difficult to separate from one another. SYN: rare earth elements. [lanthanum, first element of the series]

lanthanum
lanthanum (La) (lan′tha-num)

A metallic element, atomic no. 57, atomic wt. 138.9055; first of the rare earth elements (lanthanides). [G. lanthano, to lie hidden]
l. nitrate La(NO₃)₃;used in electron microscopy as a stain for extracellular mucopolysaccharides.

lanthionine
lanthionine (lan-thi′o-nen)

3,3′-Thiodialanine;an amino acid obtained from wood that resembles cystine but has only one sulfur atom in the molecule rather than two; i.e., a sulfide rather than a disulfide.

lanugo
lanugo (la-noo′go) [TA]

SYN: downy hair. [L. down, wooliness, from lana, wool]

Lanz
Lanz

Otto, Swiss surgeon in Amsterdam, 1865–1935. See L. line.

LAO
LAO

Abbreviation for left anterior oblique projection, used in chest radiography, especially to assess the size of the left atrium and ventricle.

LAP
LAP

Abbreviation for leukocyte alkaline phosphatase. See alkaline phosphatase.

laparo- laparo-

The loins (less properly, the abdomen in general). [G. lapara, flank, loins]

laparocele
laparocele (lap′a-ro-sel)

SYN: abdominal hernia. [laparo- + G. kele, hernia]

laparoendoscopic
laparoendoscopic (lap′a-ro-en-do-skop′ik)

Having to do with the introduction of a laparoscope into the abdominal cavity for a variety of intracavitary procedures.

laparogastroscopy
laparogastroscopy (lap′a-ro-gas-tros′ko-pe)

Inspection of interior of the stomach after a gastrotomy. [laparo- + G. gaster, stomach, + skopeo, to view]

laparomyositis
laparomyositis (lap′a-ro-mi′o-si′tis)

Inflammation of the lateral abdominal muscles. [laparo- + G. mys, muscle, + -itis, inflammation]

laparorrhaphy
laparorrhaphy (lap′a-ror′a-fe)

SYN: celiorrhaphy.

laparosalpingo-oophorectomy
laparosalpingo-oophorectomy (lap′a-ro-sal′ping-go-o-of′o-rek′to-me)

Removal of the uterine tube and ovary through an abdominal incision.

laparoscope
laparoscope (lap′a-ro-skop)

An endoscope for examining the peritoneal cavity. SYN: peritoneoscope. [laparo- + G. skopeo, to view]

laparoscopy
laparoscopy (lap-a-ros′ko-pe)

Examination of the contents of the abdominopelvic cavity with a laparoscope passed through the abdominal wall. SEE ALSO: peritoneoscopy. SYN: abdominoscopy.L. first became clinically practicable with the development of fiberoptics in the 1960s and of high-intensity, low-heat halogen bulbs in the 1970s. The technique has become standard, in selected cases, for many routine surgical procedures formerly requiring laparotomy, such as appendectomy, cholecystectomy, inguinal herniorrhaphy, oophorectomy, a second look after excision of an ovarian tumor, and diagnostic evaluation of endometriosis and female infertility. The peritoneal cavity is first inflated with CO₂ gas, and the laparoscope passed through a small incision in the abdominal wall. A second incision is usually required to provide surgical access to the area of interest. An elaborate armamentarium of surgical instruments has been developed to perform incision, drainage, excision, cautery, ligation, suturing, and other procedures with the laparoscope. The risk of intraoperative and postoperative complications, the cost of treatment, and hospitalization time are generally less with laparoscopic surgery than with traditional open procedures.
closed l. l. performed after insufflation of the abdominal cavity using a percutaneously placed needle.
open l. l. performed after insufflation of the abdomen using a trocar placed under direct vision after making a small celiotomy incision.

laparotomy
laparotomy (lap′a-rot′o-me)

1. Incision into the loin. 2. SYN: celiotomy. [laparo- + G. tome, incision]

Lapicque
Lapicque

Louis, French physiologist, 1866–1952. See L. law.

lapinization
lapinization (lap′i-ni-za′shun)

Serial passage of a virus or vaccine in rabbits. [Fr. lapin, rabbit]

lapinized
lapinized (lap′i-nizd)

Denoting viruses which have been adapted to develop in rabbits by serial transfers in this species. [Fr. lapin, rabbit]

Laplace
Laplace

Ernest, U.S. surgeon, 1861–1924. See L. forceps.

Laplace
Laplace

Pierre S. de, French mathematician, 1749–1827. See L. law.

Laquer
Laquer

Ernst, German physiologist, *1910. See L. stain for alcoholic hyalin.

lard
lard

SYN: adeps (2) . [L. lardum]
benzoinated l. used as a lubricant, in the manufacture of soap, for oiling wool, and as an illuminant. Formerly used as an ointment base.

larkspur
larkspur (lark′sper)

SYN: Delphinium ajacis.

Laron
Laron

Zvi, Israeli pediatric endocrinologist, *1927. See L. type dwarfism.

Laroyenne
Laroyenne

Lucien, French surgeon, 1831–1902. See L. operation.

Larrey
Larrey

Baron Dominique Jean de, French surgeon, 1766–1842. See L. cleft.

Larsen
Larsen

Loren J., U.S. orthopedic surgeon, *1914. See L. syndrome.

Larsson
Larsson

Tage Konrad Leopold, Swedish scientist, *1905. See Sjögren-L. syndrome.

larva
larva, pl .larvae (lar′va, lar′ve)

1. The wormlike developmental stage or stages of an insect or helminth that are markedly different from the adult and undergo subsequent metamorphosis; a grub, maggot, or caterpillar. 2. The second stage in the life cycle of a tick; the stage which hatches from the egg and, following engorgement, molts into the nymph. 3. The young of fishes or amphibians which often differ in appearance from the adult. [L. a mask]
filariform l. infective third-stage l. of the hookworm, Ascaris, and other nematodes with penetrating larvae or with larvae that migrate through the body to reach the intestine.
rhabditiform l. early developmental larval stages (first and second) of soil-borne nematodes such as Necator, Ancylostoma, and Strongyloides, which precede the infectious third-stage filariform l..

larvaceous
larvaceous (lar-va′shus)

SYN: larvate.

larva currens
larva currens (lar′va kur′enz)

Cutaneous larva migrans caused by rapidly moving larvae of Strongyloides stercoralis (up to 10 cm per hr), typically extending from the anal area down the upper thighs and observed as a rapidly progressing linear urticarial trail; may also be caused by zoonotic species of Strongyloides. [L. larva, mask + currens, racing]

larval
larval (lar′val)

1. Relating to larvae. 2. SYN: larvate.

larva migrans
larva migrans (lar′va mi′granz)

A larval worm, typically a nematode, that wanders for a period in the host tissues but does not develop to the adult stage; this usually occurs in unusual hosts that inhibit normal development of the parasite. [L. larva, mask, + migro, to transfer, migrate]
cutaneous l. a migratory serpiginous or netlike tunneling in the skin, with marked pruritus, caused by wandering hookworm larvae not adapted to intestinal maturation in humans; especially common in the eastern and southern coastal U.S. and other tropical and subtropical coastal areas; various hookworms of dogs and cats have been implicated, chiefly Ancylostoma braziliense of dog and cat feces from beaches and sandboxes in the U.S., but also Ancylostoma caninum of dogs, Uncinaria stenocephala, the European dog hookworm, and Bunostomum phlebotomum, the cattle hookworm; Strongyloides species of animal origin may also contribute to human cutaneous l.. SYN: ancylostoma dermatitis, creeping eruption, cutaneous ancylostomiasis, ground itch, water itch (1) .
ocular l. visceral l. involving the eyes, primarily of older children; clinical symptoms include decreased visual acuity and strabismus.
spiruroid l. extraintestinal migration by nematode larvae of the order Spiruroidea, not adapted to maturation in the human intestine; caused chiefly by species of Gnathostoma spinigerum and G. hispidum in Japan and Thailand, following ingestion of uncooked fish infected with encapsulated third-stage infective larvae, and possibly by ingestion of infected copepods (the first intermediate host) in contaminated drinking water; the anteriorly spined larvae produce serpiginous tunnels in the skin or may cause subcutaneous or pulmonary abscess, or may invade the eye or brain.
visceral l. a disease, chiefly of children, caused by ingestion of infective ova of Toxocara canis, less commonly by other ascarid nematodes not adapted to humans, whose larvae hatch in the intestine, penetrate the gut wall, and wander in the viscera (chiefly the liver) for periods of up to 18–24 months; may be asymptomatic or may be marked by hepatomegaly (with granulomatous lesions caused by encapsulated larvae in the enlarged liver), pulmonary infiltration, fever, cough, hyperglobulinemia, and sustained high eosinophilia.

larvate
larvate (lar′vat)

Masked or concealed; applied to a disease with undeveloped, absent, or atypical symptoms. SYN: larvaceous, larval (2) . [L. larva, mask]

larvicidal
larvicidal (lar-vi-si′dal)

Destructive to larvae.

larvicide
larvicide (lar′vi-sid)

An agent that kills larvae. [larva + L. caedo, to kill]

larviparous
larviparous (lar-vip′a-rus)

Larvae-bearing; denoting passage of larvae, rather than eggs, from the body of the female, as in certain nematodes and insects. [larva + L. pario, to bear]

larviphagic
larviphagic (lar′vi-fa′jik)

Consuming larvae; certain l. fish are used in mosquito control. [larva + G. phago, to eat]

laryng- laryng-

See laryngo-.

laryngeal
laryngeal (la-rin′je-al)

Relating in any way to the larynx.

laryngectomee
laryngectomee (lar-in-jek′to-me)

A person who has had a laryngectomy.

laryngectomy
laryngectomy (lar′in-jek′to-me)

Excision of the larynx. [laryngo- + G. ektome, excision]
horizontal l. SYN: partial l..
partial l. incomplete resection of the larynx in which the supraglottic portion is removed preserving the vocal cords. SYN: horizontal l., supraglottic l..
supraglottic l. SYN: partial l..

larynges
larynges (la-rin′jez)

Plural of larynx. [L.]

laryngismus
laryngismus (lar-in-jiz′mus)

A spasmodic narrowing or closure of the rima glottidis. [L. fr. G. larynx, + -ismos, -ism]
l. stridulus a spasmodic closure of the glottis, causing noisy inspiration. Cf.:laryngitis stridulosa. SYN: pseudocroup, spasmus glottidis.

laryngitic
laryngitic (lar-in-jit′ik)

Relating to or caused by laryngitis.

laryngitis
laryngitis (lar-in-ji′tis)

Inflammation of the mucous membrane of the larynx. [laryngo- + G. -itis, inflammation]
chronic posterior l. a form of l. involving principally the interarytenoid area; thought to be caused by regurgitation of gastric contents.
chronic subglottic l. SYN: chorditis vocalis inferior.
croupous l. inflammation of the subglottic larynx associated with respiratory infection and croupy or noisy breathing.
membranous l. a form in which there is a pseudomembranous exudate on the vocal cords.
l. sicca l. characterized by dryness and crusting of the mucous membrane of the larynx.
spasmodic l. SYN: l. stridulosa.
l. stridulosa infectious inflammation of the larynx in children, accompanied by night attacks of spasmodic closure of the glottis, causing inspiratory stridor. SYN: spasmodic l..

laryngo- laryngo-, laryng-

The larynx. [G. larynx]

laryngocele
laryngocele (la-ring′go-sel)

An air sac communicating with the larynx through the ventricle, often bulging outward into the tissue of the neck, especially during coughing and playing of wind instruments. [laryngo- + G. kele, hernia]

laryngofissure
laryngofissure (la-ring′go-fish′er)

Operative opening into the larynx, generally through the midline, commonly done for the excision of early carcinoma or the correction of laryngostenosis. SYN: median laryngotomy, thyrofissure, thyroidotomy, thyrotomy (2) .

laryngograph
laryngograph (la-ring′go-graf)

An instrument for making a tracing of the movements of the vocal folds. [laryngo- + G. grapho, to write]

laryngography
laryngography (la-rin-gog′-ra-fe)

Radiography of the larynx after coating mucosal surfaces with contrast material.

laryngology
laryngology (lar′ing-gol′o-je)

The branch of medical science concerned with the larynx and the voice; the specialty of diseases of the larynx. [laryngo- + G. logos, study]

laryngomalacia
laryngomalacia (la-ring′go-ma-la′she-a)

SYN: chondromalacia of larynx. [laryngo- + G. malakia, a softness]

laryngoparalysis
laryngoparalysis (la-ring′go-pa-ral′i-sis)

Paralysis of the laryngeal muscles. SYN: laryngoplegia.

laryngopharyngeal
laryngopharyngeal (la-ring′go-fa-rin′je-al)

Relating to both larynx and pharynx or to the laryngopharynx.

laryngopharyngectomy
laryngopharyngectomy (la-ring′go-far′in-jek′to-me)

Resection or excision of both larynx and pharynx.

laryngopharyngeus
laryngopharyngeus (la-ring′go-far′in-je′us)

SYN: inferior constrictor (muscle) of pharynx. [L.]

laryngopharyngitis
laryngopharyngitis (la-ring′go-far-in-ji′tis)

Inflammation of the larynx and pharynx.

laryngopharynx
laryngopharynx (la-ring′go-far-ingks) [TA]

The part of the pharynx lying below the aperture of the larynx and behind the larynx; it extends from the vestibule of the larynx to the esophagus at the level of the inferior border of the cricoid cartilage. SYN: pars laryngea pharyngis [TA] , hypopharynx&star, laryngeal part of pharynx, laryngeal pharynx.

laryngophthisis
laryngophthisis (la-ring′go-thi′sis)

Tuberculosis of the larynx. [laryngo- + G. phthisis, a wasting]

laryngoplasty
laryngoplasty (la-ring′go-plas-te)

Reparative or plastic surgery of the larynx. [laryngo- + G. plasso, to form]

laryngoplegia
laryngoplegia (la-ring′go-ple′je-a)

SYN: laryngoparalysis. [laryngo- + G. plege, stroke]

laryngoptosis
laryngoptosis (la-ring-go-to′sis)

An abnormally low position of the larynx, which may be congenital or acquired; does not impair the health of the neonate. Some degree of l. occurs with aging. [laryngo- + G. ptosis, a falling]

laryngoscope
laryngoscope (la-ring′go-skop)

Any of several types of tubes, equipped with electrical lighting, used in examining or operating upon the interior of the larynx through the mouth. [laryngo- + G. skopeo, to inspect]

laryngoscopic
laryngoscopic (la-ring′go-skop′ik)

Relating to laryngoscopy.

laryngoscopist
laryngoscopist (lar′ing-gos′ko-pist)

A person skilled in the use of the laryngoscope.

laryngoscopy
laryngoscopy (lar′ing-gos′ko-pe)

Inspection of the larynx by means of the laryngoscope.
direct l. inspection of the larynx by means of either a hollow instrument or a fiberoptic cable.
indirect l. inspection of the larynx by means of a reflected image on a mirror.
suspension l. support of the laryngoscope by leverage from a supportive structure to provide maximum exposure of the pharyngeal cavity and larynx.
transnasal fiberoptic l. l. performed with a fiberoptic endoscope introduced through the nose.

laryngospasm
laryngospasm (la-ring′go-spazm)

Spasmodic closure of the glottic aperture. SYN: glottidospasm, laryngospastic reflex.

laryngostenosis
laryngostenosis (la-ring′go-ste-no′sis)

Stricture or narrowing of the lumen of the larynx. [laryngo- + G. stenosis, a narrowing]

laryngostomy
laryngostomy (lar′ing-gos′to-me)

The establishment of a permanent opening from the neck into the larynx. [laryngo- + G. stoma, mouth]

laryngostroboscope
laryngostroboscope (la-ring′go-stro′bo-skop, -strob′o-skop)

Apparatus for observing the motion of the vocal folds during phonation with intermittent illumination. As the frequency of illumination approaches the frequency of opening and closing of the vocal cords, they appear to be still.

laryngotomy
laryngotomy (lar-ing-got′o-me)

A surgical incision of the larynx. [laryngo- + G. tome, incision]
inferior l. SYN: cricothyrotomy.
median l. SYN: laryngofissure.
superior l. incision through the thyrohyoid membrane.

laryngotracheal
laryngotracheal (la-ring′go-tra′ke-al)

Relating to both larynx and trachea.

laryngotracheitis
laryngotracheitis (la-ring′go-tra-ke-i′tis)

Inflammation of both larynx and trachea.

laryngotracheobronchitis
laryngotracheobronchitis (la-ring′go-tra′ke-o-brong-ki′tis)

An acute respiratory infection involving the larynx, trachea, and bronchi. See croup.

laryngotracheoplasty
laryngotracheoplasty (lar-ing′go-tra′ke-o-plas′te)

Operation to repair subglottic stenosis.

larynx
larynx, pl .larynges (lar′ingks, la-rin′jez)

The organ of voice production; the part of the respiratory tract between the pharynx and the trachea; it consists of a framework of cartilages and elastic membranes housing the vocal folds and the muscles which control the position and tension of these elements. [Mod. L. fr. G.]
Cooper-Rand artificial l. an electronic device for vocal rehabilitation after laryngectomy that produces an intraoral sound articulated into speech with the pharynx, palate, tongue, lips, and teeth.

lase
lase (laz)

To cut, divide, or dissolve a substance, or to treat an anatomical structure, with a laser beam.

Lasègue
Lasègue

Ernest C., French physician, 1816–1883. See L. sign, L. syndrome.

laser
laser (la′zer)

1. (noun) A device that concentrates high energies into an intense narrow beam of nondivergent monochromatic electromagnetic radiation; used in microsurgery, cauterization, and for a variety of diagnostic purposes. Lasers can be based on numerous chemical sources, gas, liquid, and solid, some of which are listed in chart. Lasers are widely used in printers of text or x-ray images. 2. (verb) To treat a structure with a l. beam. [acronym coined from light amplification by stimulated emission of radiation]
argon l. l. used for ophthalmic procedures, including retinal photocoagulation and trabeculoplasty, consisting of photons in the blue (488 nm) or green (514 nm) spectrum.
continuous wave l. a l. in which energy output is constant.
excimer l. l. used particularly for refractive procedures, consisting of photons in the ultraviolet spectrum emitted by unstable dimers of argon and fluoride. [excited dimer]
krypton l. l. used for ophthalmic procedures, particularly retinal photocoagulation in the presence of vitreous hemorrhage, consisting of photons in the red (647 nm) spectrum.
KTP l. l. in the blue-green to green (532 nm) spectrum, used for hemostasis; produced by doubling the frequency of an Nd:YAG l. by passing the beam through a KTP crystal. [K (potassium) Titanyl Phosphate]
Nd:YAG l. l. in the infrared spectrum (1064 nm), with a greater depth of penetration than other lasers. [Nd (neodymium) + Yttrium-A luminum-Garnet]
pulsed l. a l. in which energy output is pulsed, allowing short bursts of high energy.
pulsed dye l. extremely short bursts of focused yellow light absorbed by hemoglobin, used to treat hemangiomas without anesthesia in young children.
pumped l. a l. whose energy level is increased by the application of separate sources of electrons or photons, which may themselves be primary lasers.
Q-switched l. (quality-switched); a l. in which the quality, or energy storage capacity is altered between a very high and a low value.
quasi-continuous wave l. a l. whose output can be controlled in milliseconds or similarly small increments by electronic control.

lasering
lasering (la′zer-ing)

The use of a laser beam to cut, divide, or dissolve a substance, or to treat an anatomical structure.

laser plume
laser plume

The production of smoke with laser ablation; can cause respiratory difficulty for operative personnel. [L. pluma, feather]

Lash
Lash

Abraham Fae, U.S. obstetrician-gynecologist, *1898. See L. operation.

lash
lash

An eyelash.

LASIK
LASIK

Acronym for laser-assisted in situ keratomileusis.

Lasiohelea
Lasiohelea (las′e-o-he′le-a)

A genus of small bloodsucking gnats.

lassitude
lassitude (las′i-tood)

A sense of weariness. [L. lassitudo, fr. lassus, weary]

latah
latah (lah′tah)

One of the pathologic startle syndromes. A culture-bound disorder characterized by an exaggerated physical response to being startled or to unexpected suggestion, the subjects involuntarily uttering cries or executing movements in response to command or in imitation of what they hear or see in others. SEE ALSO: jumping disease. [Malay, ticklish]

Latarget
Latarget

André, French anatomist, 1877–1947. See L. nerve, L. vein.

latebra
latebra (lat′e-bra)

A flask-shaped region in large-yolked eggs extending from the animal pole to a dilated terminal portion near the center of the yolk; it contains the main bulk of the white yolk. [L. hiding place]

latency
latency (la′ten-se)

1. The state of being latent. 2. In conditioning, or other behavioral experiments, the period of apparent inactivity between the time the stimulus is presented and the moment a response occurs. 3. In psychoanalysis, the period of time from approximately age five to puberty.

latent
latent (la′tent)

Not manifest, dormant, but potentially discernible. [L. lateo, pres. p. latens (-ent-), to lie hidden]

laterad
laterad (lat′er-ad)

Toward the side. [L. latus, side, + ad, to]

lateral
lateral (lat′er-al) [TA]

1. On the side. SYN: lateralis [TA] . 2. Farther from the median or midsagittal plane. SYN: lateralis [TA] . 3. In dentistry, a position either right or left of the midsagittal plane. 4. A radiographic projection made with the film in the sagittal plane; especially, the second view of a chest series. SYN: lateralis [TA] . [L. lateralis, l., fr. latus, side]

lateralis
lateralis (lat-er-a′lis) [TA]

SYN: lateral (1) , lateral (2) , lateral. [L.]

laterality
laterality (lat-er-al′i-te)

Referring to a side of the body or of a structure; specifically, the dominance of one side of the brain or the body.
crossed l. right dominance of some members, e.g., arm or leg, and left dominance of other members.

lateralization
lateralization (lat′er-al-i-za′shun)

The process whereby certain embryological asymmetries of structure (such as the right-side location of the liver and the structure of the great vessels) and function (handedness) are ordained phylogenetically, coded genetically, and realized ontogenetically.

lateriflexion
lateriflexion, lateriflection (lat-er-i-flek′shun)

SYN: lateroflexion.

latero- latero-

Lateral, to one side. [L. lateralis, lateral, fr. latus, side]

lateroabdominal
lateroabdominal (lat′er-o-ab-dom′i-nal)

Relating to the sides of the abdomen, to the loins or flanks.

laterodeviation
laterodeviation (lat′er-o-de-ve-a′shun)

A bending or a displacement to one side. [latero- + L. devio, to turn aside, fr. via, a way]

lateroduction
lateroduction (lat′er-o-duk′shun)

A drawing to one side; denoting turning of the eyeball away from the midline. SYN: exduction. [latero- + L. duco, pp. ductus, to lead]

lateroflexion
lateroflexion, lateroflection (lat′er-o-flek′shun)

A bending or curvature to one side. SYN: lateriflexion, lateriflection. [latero- + L. flecto, pp. flexus, to bend]

lateroposition
lateroposition (lat′er-o-po-zish′un)

A shift to one side.

lateropulsion
lateropulsion (lat′er-o-pul′shun)

An involuntary sidewise movement occurring in certain nervous affections. [latero- + L. pello, pp. pulsus, to push, drive]

laterotorsion
laterotorsion (lat′er-o-tor′shun)

A twisting to one side; denoting rotation of the eyeball around its anteroposterior axis, so that the top part of the cornea turns away from the sagittal plane. [latero- + L. torsio, a twisting]

laterotrusion
laterotrusion (lat′er-o-troo′zhun)

The outward thrust given by the muscles of mastication to the rotating mandibular condyle during movement of the mandible. [latero- + L. trudo, pp. trusus, to thrust]

lateroversion
lateroversion (lat′er-o-ver′shun)

Version to one side or the other, denoting especially a malposition of the uterus. [latero- + L. verto, pp. versus, to turn]

latex
latex (la′teks)

1. An emulsion or suspension produced by some seed plants; it contains suspended microscopic globules of natural rubber. 2. Similar synthetic materials such as polystyrene, polyvinyl chloride, etc. [L. liquid]

lathe
lathe (ladh)

A motor-driven machine with a rotating shaft that can be fitted with various types of cutting instruments, grinding stones and polishing wheels; used in finishing and polishing dental appliances.

lathyrism
lathyrism (lath′i-rizm)

A disease occurring in Ethiopia, Algeria, and India, characterized by various nervous manifestations, tremors, spastic paraplegia, and paresthesias; prevalent in districts where vetches, khasari (Lathyrus sativus), and allied species form the main food. Experimentally, a form of bone disease induced in laboratory animals by feeding L. sativus peas, or a principle derived from them, especially β-aminoproprionitrile. SYN: lupinosis. [L. lathyrus, vetch]

lathyrogen
lathyrogen (lath′i-ro-jen)

An agent or drug, occurring naturally or used experimentally, that induces lathyrism.

Latin square
Latin square

A statistical design for experiments that removes from experimental error the variation from two sources that may be identified with the rows and columns of a square. The allocation of experimental treatments is such that each treatment occurs exactly once in each row and column. For example, a design for a 5 × 5 square is as follows:

latitude
latitude (la′ti-tood)

The range of light or x-ray exposure acceptable with a given photographic emulsion. See l. film. SYN: digital gray scale, gray scale. [L. latitudo, width, fr. latus, wide]

Latrodectus
Latrodectus (lat-ro-dek′tus)

A genus of relatively small spiders, the widow spiders, capable of inflicting highly poisonous, neurotoxic, painful bites; they are responsible, along with Loxosceles species (the brown spiders), for most of the severe reactions from spider envenomation. Medically important species are known from Australia, North and South America, South Africa, and New Zealand. Some venomous species, in addition to L. mactans (the black widow spider), are L. bishopi (the red-legged widow spider), L. euracaviensis, L. geometricus, and L. tredecimguttatus. [L. latro, servant, robber, + G. dektes, a biter]
L. mactans the black widow spider, a venomous jet-black spider found in protected dark places; it is especially common in the southern U.S.; the full-grown female (slightly more than 1 cm long) has a brilliant red dumbbell- or hourglass-shaped mark on the ventral aspect of the abdomen, and her bite may be extremely painful, producing a syndrome mimicking an acute abdominal crisis; some deaths, though rare, have been reported, particularly in small children; the male spider lacks the hourglass mark and is not venomous.

LATS
LATS

Abbreviation for long-acting thyroid stimulator.

lattice
lattice (lat′is)

A regular arrangement of units into an array such that a plane passing through two units of a particular type or in a particular interrelationship will pass through an indefinite number of such units; e.g., the atom arrangement in a crystal.

latus
latus, gen. lateris, pl .latera (la′tus, lat′er-is, lat′er-a) [TA]

SYN: flank. [L. side]

Latzko
Latzko

Wilhelm, Austrian obstetrician, 1863–1945. See L. cesarean section.

laudable
laudable (law′da-bl)

A term from the past used to describe a quality of pus (thick and creamy) that suggested the wound would ultimately heal through granulation process and not be associated with sepsis and death. [L. laudabilis, praiseworthy]

laudanine
laudanine (law′da-nen)

An isoquinoline alkaloid derived from the mother liquor of morphine; it causes tetanoid convulsions, with action similar to that of strychnine.

laudanosine
laudanosine (law′da-no-sen)

An isoquinoline alkaloid obtained from the mother liquor of morphine; it causes tetanic convulsions.

laudanum
laudanum (law′da-num)

A tincture containing opium. [G. ledanon, a resinous gum]

Laugier
Laugier

Stanislas, French surgeon, 1799–1872. See L. hernia.

Laumonier
Laumonier

Jean B.P.N.R., French surgeon, 1749–1818. See L. ganglion.

Launois
Launois

Pierre E., French physician, 1856–1914. See L.-Cléret syndrome, L.-Bensaude syndrome.

Laurence
Laurence

John Zachariah, British ophthalmologist, 1830–1874. See L.-Moon syndrome.

Laurer
Laurer

Johann F., German pharmacologist, 1798–1873. See L. canal.

lauric acid
lauric acid (law′rik)

A fatty acid occurring in spermaceti, in milk, and in laurel, coconut, and palm oils as well as waxes and marine fats. SYN: n-dodecanoic acid.

Lauth
Lauth

Charles, English chemist, 1836–1913. See L. violet.

Lauth
Lauth

Ernst A., German physician, 1803–1837. See L. canal.

Lauth
Lauth

Thomas, German anatomist and surgeon, 1758–1826. See L. ligament.

Lauth violet
Lauth violet

SYN: thionine.

LAV
LAV

Abbreviation for lymphadenopathy-associated virus.

lavage
lavage (la-vahzh′)

The washing out of a hollow cavity or organ by copious injections and rejections of fluid. [Fr. from L. lavo, to wash]
antral l. irrigation of the maxillary sinus through its natural ostium or through a puncture of the inferior meatus.
bronchoalveolar l. (BAL) procedure for analyzing the cellular milieu of the alveoli (including microbiology, types of inflammatory cells) by use of a bronchoscope or other hollow tube through which saline is instilled into distal bronchi and then withdrawn.

Lavdovsky
Lavdovsky

Michail D., Russian histologist, 1846–1902. See L. nucleoid.

Laverania
Laverania (lav-er-a′ne-a)

Old generic name for malaria-causing and other hematozoan protozoa. L. falciparum is a distinctive generic name for Plasmodium falciparum, and is preferred by some who believe that crescentic gametocytes should be the basis for classifying the causal agent of falciparum malaria in a separate genus. See Plasmodium, Haemoproteus. [C. Laveran, Fr. protozoologist and Nobel laureate, 1845–1922]

laveur
laveur (la-vur′)

An instrument for irrigation or lavage. [Fr.]

law
law (law)

1. A principle or rule. 2. A statement of fact detailing a sequence or relation of phenomena that is invariable under given conditions. SEE ALSO: principle, rule, theorem. [A.S. lagu]
Alexander l. states that a jerky nystagmus becomes worse when gazing in the direction of the fast component.
all or none l. SYN: Bowditch l..
Ångström l. a substance absorbs light of the same wavelength as it emits when luminous.
Arndt l. obsolete l. stating that weak stimuli excite physiologic activity, moderately strong ones favor it, strong ones retard it, and very strong ones arrest it.
Arrhenius l. SYN: Arrhenius doctrine.
laws of association principles formulated by Aristotle to account for the functional relationships between ideas; the l. of contiguity (association) proved most useful to experimental psychologists, culminating in modern studies of respondent conditioning.
l. of average localization visceral pain is most accurately localized in the least mobile viscera and least accurately in the most mobile.
Avogadro l. equal volumes of gases contain equal numbers of molecules, the conditions of pressure and temperature being the same. SYN: Ampère postulate, Avogadro hypothesis, Avogadro postulate.
Baer l. the general organ characteristics found in all members of a group appear earlier in embryogenesis than the special organ characteristics that distinguish specific members of the group; this l. is the predecessor of the recapitulation theory.
Baruch l. the effect of any hydriatric procedure is in direct proportion to the difference between the temperature of the water and that of the skin; when the temperature of the water is above or below that of the skin the effect is stimulating; when the two temperatures are the same the effect is sedative.
Beer l. the intensity of a color or of a light ray is inversely proportional to the depth of liquid through which it is transmitted; it is concluded that the absorption is dependent upon the number of molecules in the path of the ray. Cf.:Beer-Lambert l..
Beer-Lambert l. the absorbance of light is directly proportional to the thickness of the media through which the light is being transmitted multiplied by the concentration of absorbing chromophore; i.e., A = εbc where A is the absorbance, ε is the molar extinction coefficient, b is the thickness of the solution, and c is the concentration.
Behring l. parenteral administration of serum from an immunized person provides a relative, passive immunity to that disease ( i.e., prevents it, or favorably modifies its course) in a previously susceptible person.
Bell l. the ventral spinal roots are motor, the dorsal are sensory. SYN: Bell-Magendie l., Magendie l..
Bell-Magendie l. SYN: Bell l..
Bernoulli l. when friction is negligible, the velocity of flow of a gas or fluid through a tube is inversely related to its pressure against the side of the tube; i.e., velocity is greatest and pressure lowest at a point of constriction. SYN: Bernoulli principle, Bernoulli theorem.
Berthollet l. salts in solution will always react with each other so as to form a less soluble salt, if possible.
biogenetic l., l. of biogenesis SYN: recapitulation theory.
Blagden l. the depression of the freezing point of dilute solutions is proportional to the amount of the dissolved substance.
Bowditch l. consistently total response to any effective stimulus. SYN: all or none l..
Boyle l. at constant temperature, the volume of a given quantity of gas varies inversely with its absolute pressure. SYN: Mariotte l..
Broadbent l. lesions of the upper segment of the motor tract cause less marked paralysis of muscles that habitually produce bilateral movements than of those that commonly act independently of the opposite side.
Bunsen-Roscoe l. in two photochemical reactions, e.g., the darkening of a photographic plate or film, if the products of the intensity of illumination and the time of exposure are equal, the quantities of chemical material undergoing change will be equal; the retina for short periods of exposure obeys this l.. SYN: reciprocity l., Roscoe-Bunsen l..
Charles l. all gases expand equally on heating, namely, 1273.16 of their 0°C volume for every additional degree Celsius. SYN: Gay-Lussac l..
l. of constant numbers in ovulation the number of ova discharged at each ovulation is nearly constant for any given species.
l. of contiguity when two ideas or psychologically perceived events have once occurred in close association they are likely to so occur again, the subsequent occurrence of one tending to elicit the other; this l. figures prominently in modern theories of conditioning and learning.
l. of contrary innervation SYN: Meltzer l..
Coppet l. solutions having the same freezing point have equal concentrations of dissolved substances.
Courvoisier l. painless enlargement of the gallbladder with jaundice is likely to result from carcinoma of the head of the pancreas and not from a stone in the common duct, because in the latter the gallbladder is usually scarred from infection and does not distend. SYN: Courvoisier sign.
Dale-Feldberg l. an identical chemical transmitter is liberated at all the functional terminals of a single neuron.
Dalton l. each gas in a mixture of gases exerts a pressure proportionate to the percentage of the gas and independent of the presence of the other gases present. SYN: l. of partial pressures.
Dalton-Henry l. in dissolving a mixture of gases, a liquid will absorb as much of each gas in the mixture as if that were the only gas dissolved.
l. of definite proportions the relative weights of the several elements forming a chemical compound are invariable. SYN: Proust l..
l. of denervation when a structure is denervated, its irritability to certain chemical agents is increased; e.g., the greater sensitivity of the pupil to acetylcholine after section and degeneration of the third nerve, and of the nictitating membrane to adrenaline after excision of the superior cervical ganglion.
Descartes l. SYN: l. of refraction.
Donders l. the rotation of the eyeball is determined by the distance of the object from the median plane and the line of the horizon.
Draper l. a chemical change is produced in a photochemical substance only by those light rays that are absorbed by that substance.
Du Bois-Reymond l. SYN: l. of excitation.
Dulong-Petit l. the specific heats of many solid elements are inversely proportional to their atomic weights.
Einthoven l. in the electrocardiogram the potential of any wave or complex in lead II is equal to the sum of its potentials in leads I and III. SYN: Einthoven equation.
Elliott l. adrenaline acts upon those structures innervated by sympathetic nerve fibers.
l. of excitation a motor nerve responds, not to the absolute value, but to the alteration of value from moment to moment, of the electric current; i.e., rate of change of intensity of the current is a factor in determining its effectiveness. SYN: Du Bois-Reymond l..
Faraday laws 1. the amount of an electrolyte decomposed by an electric current is proportional to the amount of the current; 2. when the same current is passed through several electrolytes, the amounts of the different substances decomposed are proportional to their chemical equivalents.
Farr laws a set of mathematical formulae, axioms, and laws first enunciated in the annual reports submitted by William Farr to the Registrar General of England and Wales from 1839 to 1883. The laws deal with the relationship of incidence to prevalence, the natural history of epidemics, and mathematical features of common types of epidemic. [Derived from the writings of William Farr, British medical statistician]
Fechner-Weber l. SYN: Weber-Fechner l..
Ferry-Porter l. the critical fusion is directly proportional to the logarithm of the light intensity.
Fick laws of diffusion 1. the direction of movement of solutes by diffusion is always from a higher to a lower concentration and the diffusive flux J_A of solute A across a plane at x is proportional to the concentration gradient of A at x; i.e., J_A = −D(C_A/x); 2. the increase of concentration of solute A with time, C_A/t, is directly proportional to the change in the concentration gradient, i.e., C_A/t = D(fl²/x²).
Flatau l. a l. concerning the excentric position of the long spinal tracts; the greater the distance the nerve fibers run lengthwise in the cord, the more they tend to be situated toward its periphery.
Galton l. in a population mating at random, the progeny of a parent with an extreme value for a measurable phenotype will tend on average to have values nearer the population mean than in the extreme parent. SEE ALSO: l. of regression to mean. SYN: l. of regression to mean.
Gay-Lussac l. SYN: Charles l..
Godélier l. tuberculosis of the peritoneum is always associated with tuberculosis of the pleura on one or both sides.
Gompertz l. the proportional relationship of mortality to age; after age 35–40, the increase in mortality with age tends to be logarithmic.
Graham l. the relative rapidity of diffusion of two gases varies inversely as the square root of their densities, i.e., their molecular weights.
Grasset l. SYN: Landouzy-Grasset l..
l. of gravitation SYN: Newton l..
Guldberg-Waage l. SYN: l. of mass action.
Haeckel l. SYN: recapitulation theory.
Halsted l. transplanted tissue will grow only if there is a lack of that tissue in the host.
Hardy-Weinberg l. if mating occurs at random with respect to any one autosomal locus in a population in which the gene frequencies are equal in the two sexes, and the factors tending to change gene frequencies (mutation, differential selection, migration) are either absent or negligible, then in one generation the probabilities of all possible genotypes will on average equal the same proportions as if the genes were assembled at random. The l. does not apply to two or more loci jointly, nor to X-linked traits where the initial gene frequencies differ in the two sexes.
l. of the heart the energy liberated by the heart when it contracts is a function of the length of its muscle fibers at the end of diastole. SYN: Starling l..
Heidenhain l. glandular secretion is always accompanied by an alteration in the structure of the gland.
Hellin l. twins occur once in 89 births, triplets once in 89², and quadruplets once in 89³. If the frequency of twins in a population is p, the frequency of triplets is p², and the frequency of quadruplets is p³.
Henry l. at equilibrium, at a given temperature, the amount of gas dissolved in a given volume of liquid is directly proportional to the partial pressure of that gas in the gas phase (this is only true for gases that do not react chemically with the solvent).
Herring l. states that paired agonist muscles from each eye operating in the same field of gaze receive equal innervation while paired antagonist muscles receive equal inhibition.
Hess l. the amount of heat generated by a reaction is the same whether the reaction takes place in one step or several steps; i.e., ΔH values (and thus ΔG values) are additive.
Hilton l. the nerve supplying a joint supplies also the muscles which move the joint and the skin covering the articular insertion of those muscles.
Hooke l. the stress applied to stretch or compress a body is proportional to the strain, or change in length thus produced, so long as the limit of elasticity of the body is not exceeded.
l. of independent assortment genes that are not alleles assort independently when the gametes are formed; traits at linked loci are an exception. SYN: Mendel second l..
l. of intestine SYN: myenteric reflex.
inverse square l. as applied to point sources, the intensity of radiation diminishes in proportion to the square of the distance from the source.
isodynamic l. for energy purposes, the different foodstuffs may replace one another in accordance with their caloric values when burned in a calorimeter.
Jackson l. loss of mental functions due to disease retraces in reverse order its evolutionary development.
Koch l. SYN: Koch postulates, under postulate.
Lambert l. 1. each layer of equal thickness absorbs an equal fraction of the light that traverses it. Cf.:Beer-Lambert l.. 2. the illumination of a surface on which the light falls normally from a point source is inversely proportional to the square of the distance from the source.
Landouzy-Grasset l. in lesions of one hemisphere, the patient's head is turned to the side of the affected muscles if there is spasticity and to that of the cerebral lesion if there is paralysis. SYN: Grasset l..
Lapicque l. the chronaxie is inversely proportional to the diameter of an axon.
Laplace l. the equilibrium relationship between transmural pressure difference (ΔP), wall tension (T), and radius of curvature (R) in a concave surface; for a sphere: ΔP = 2T/R; for a cylinder: ΔP = T/R.
Le Chatelier l. if external factors such as temperature and pressure disturb a system in equilibrium, adjustment occurs in such a way that the effect of the disturbing factors is reduced to a minimum. SYN: Le Chatelier principle.
Listing l. when the eye leaves one object and fixes upon another, it revolves about an axis perpendicular to a plane cutting both the former and the present lines of vision.
Louis l. tuberculosis in any organ is associated with tuberculosis in the lung.
Magendie l. SYN: Bell l..
Marey l. the pulse rate varies inversely with the blood pressure; i.e., the pulse is slow when the pressure is high; an expression of baroreceptor reflex influences on heart rate.
Marfan l. the healing of localized tuberculosis protects against subsequent development of pulmonary tuberculosis.
Mariotte l. SYN: Boyle l..
mass l. SYN: l. of mass action.
l. of mass action the rate of a chemical reaction is proportional to the concentrations of the reacting substances; when the forward reaction rate equals the reverse reaction rate ( i.e., at equilibrium) then, at constant temperature, the product of the concentrations of all the products divided by the product of the concentrations of all the reactants is itself a constant (K_eq). SYN: Guldberg-Waage l., mass l..
Meltzer l. all living functions are continually controlled by two opposite forces: augmentation or action on the one hand, and inhibition on the other. SYN: l. of contrary innervation.
Mendeléeff l. the properties of elements are periodical functions of their atomic weights; i.e., if the elements are arranged in the order of their atomic weights, every element in the series will be related in respect to its properties to the eighth in order before or after it. SYN: periodic l..
Mendel first l. SYN: l. of segregation.
Mendel second l. SYN: l. of independent assortment.
l. of the minimum growth and development of plants and animals are determined by the availability of that essential nutrient which is present in the smallest amount.
Müller l. each type of sensory nerve ending, however stimulated (electrically, mechanically, etc.), gives rise to its own specific sensation; moreover, each type of sensation depends not upon any special character of the different nerves but upon the part of the brain in which their fibers terminate. SYN: l. of specific nerve energies.
l. of multiple proportions SYN: l. of reciprocal proportions.
Nasse l. an early statement of the pattern of X-linked recessive inheritance: hemophilia affects only boys but is transmitted through mothers and sisters.
Neumann l. in compounds of analogous chemical constitution, the molecular heat, or the product of the specific heat and the atomic weight, is always the same.
Newton l. the attractive force between any two bodies is proportional to the product of their masses, and inversely proportional to the square of the distance between their centers. SYN: l. of gravitation.
Nysten l. rigor mortis affects first the muscles of the head and spreads toward the feet.
Ochoa l. the content of the X-chromosome tends to be phylogenetically conserved.
Ohm l. in an electric current passing through a wire, the intensity of the current (I) in amperes equals the electromotive force (E) in volts divided by the resistance (R) in ohms: I = E/R.
l. of partial pressures SYN: Dalton l..
Pascal l. fluids at rest transmit pressure equally in every direction.
periodic l. SYN: Mendeléeff l..
Pflüger l. SYN: l. of polar excitation.
Plateau-Talbot l. when successive light stimuli follow each other sufficiently rapidly to become fused, their apparent brightness is diminished.
Poiseuille l. in laminar flow, the volume of a homogeneous fluid passing per unit time through a capillary tube is directly proportional to the pressure difference between its ends and to the fourth power of its internal radius, and inversely proportional to its length and to the viscosity of the fluid.
l. of polar excitation a given segment of a nerve is irritated by the development of catelectrotonus and the disappearance of anelectrotonus, but the reverse does not hold; i.e., excitation occurs at the cathode when the circuit is closed and at the anode when it is opened. SYN: Pflüger l..
l. of priority use of the earliest published name (senior synonym) of two or more names of an organism as the correct name.
Profeta l. the subject of congenital syphilis is immune to the acquired disease.
Proust l. SYN: l. of definite proportions.
Raoult l. the vapor pressure of a solution of a nonvolatile nonelectrolyte is that of the pure solvent multiplied by the mole-fraction of the solvent in the solution.
l. of recapitulation SYN: recapitulation theory.
l. of reciprocal proportions the relative weights in which two substances form a chemical union singly with a third are the same as, or simple multiples of, those in which they unite with each other; a corollary of the l. of definite proportions. SYN: l. of multiple proportions.
reciprocity l. SYN: Bunsen-Roscoe l..
l. of referred pain pain arises only from irritation of nerves which are sensitive to those stimuli that produce pain when applied to the surface of the body.
l. of refraction for two given media, the sine of the angle of incidence bears a constant relation to the sine of the angle of refraction. SYN: Descartes l., Snell l..
l. of regression to mean SYN: Galton l..
Ribot l. of memory in progressive dementias, remote memories tend to be preserved whereas recent memories are lost.
Ricco l. for small images, light intensity × area = constant for the threshold.
Roscoe-Bunsen l. SYN: Bunsen-Roscoe l..
Rosenbach l. 1. in affections of the nerve trunks or nerve centers, paralysis of the flexor muscles appears later than that of the extensors; 2. in cases of abnormal stimulation of organs with rhythmical functional periodicity, there is often a grouping of the individual acts with corresponding lengthening of the pauses, in such a way that the proportion of total rest and activity remains nearly the same.
Rubner laws of growth 1. the l. of constant energy consumption: the rapidity of growth is proportional to the intensity of the metabolic processes; 2. the l. of the constant growth quotient: in most young mammals, 24% of the entire food energy, or calories, is used for growth; in humans, only 5% is thus used.
Schütz l. SYN: Schütz rule.
second l. of thermodynamics the entropy of the universe moves toward a maximum; similarly, the entropy of any isolated microcosm ( e.g., a chemical reaction) proceeds spontaneously only in that direction that yields an increase in entropy, entropy being maximal at equilibrium. To quote G.N. Lewis, “Every process that occurs spontaneously is capable of doing work; to reverse any such process requires the expenditure of work from the outside.”
l. of segregation factors that affect development retain their individuality from generation to generation, do not become contaminated when mixed in a hybrid, and become sorted out from one another when the next generation of gametes is formed. SYN: Mendel first l..
Sherrington l. every dorsal spinal nerve root supplies a particular area of the skin, the dermatome (3) , which is, however, invaded above and below by fibers from the adjacent spinal segments.
l. of similars similia similibus curantur.
Snell l. SYN: l. of refraction.
Spallanzani l. the younger the individual the greater is the regenerative power of its cells.
l. of specific nerve energies SYN: Müller l..
Starling l. SYN: l. of the heart.
Stokes l. 1. a muscle lying above an inflamed mucous or serous membrane is frequently the seat of paralysis; 2. a relationship of the rate of fall of a small sphere in a viscous fluid; applicable to centrifugation of macromolecules; 3. the wavelength of light emitted by a fluorescent material is longer than that of the radiation used to excite the fluorescence.
Tait l. an obsolete dictum that an exploratory laparotomy should be performed in every case of obscure pelvic or abdominal disease that threatens health or life.
Thoma laws the development of blood vessels is governed by dynamic forces acting on their walls as follows: an increase in velocity of blood flow causes dilation of the lumen; an increase in lateral pressure on the vessel wall causes it to thicken; an increase in end-pressure causes the formation of new capillaries.
van't Hoff l. 1. in stereochemistry, all optically active substances have one or more multivalent atoms united to four different atoms or radicals so as to form in space an unsymmetrical arrangement; 2. the osmotic pressure exerted by any substance in very dilute solution is the same that it would exert if present as gas in the same volume as that of the solution; or, at constant temperature, the osmotic pressure of dilute solutions is proportional to the concentration (number of molecules) of the dissolved substance; i.e., the osmotic pressure, Π, in dilute solutions is Π = RTΣc_i, where R is the universal gas constant, T is the absolute temperature, and c_i is the molar concentration of solute i; 3. the rate of chemical reactions increases between two- and three-fold for each 10°C rise in temperature.
Vogel l. when a phenotype may be transmitted by various modes of mendelian inheritance, the dominant will have the least deleterious phenotype, the recessive the most, and the X-linked intermediate between the two.
wallerian l. after section of the posterior root of a spinal nerve between the root ganglion and the spinal cord, the central portion degenerates; after division of the anterior root, the peripheral portion degenerates; the trophic center of the posterior root is therefore the ganglion, that of the anterior root the spinal cord.
Weber l. SYN: Weber-Fechner l..
Weber-Fechner l. the intensity of a sensation varies by a series of equal increments (arithmetically) as the strength of the stimulus is increased geometrically; if a series of stimuli is applied and so adjusted in strength that each stimulus causes a just perceptible change in intensity of the sensation, then the strength of each stimulus differs from the preceding one by a constant fraction; thus, if a just perceptible change in a visual sensation is produced by the addition of 1 candle to an original illumination of 100 candles, 10 candles will be required to produce any change in sensation when the original illumination was one of 1000 candles. SYN: Fechner-Weber l., Weber l..
Weigert l. the loss or destruction of a part or element in the organic world is likely to result in compensatory replacement and overproduction of tissue during the process of regeneration or repair (or both), as in the formation of callus when a fractured bone heals. SYN: overproduction theory.
Williston l. as the vertebrate scale is ascended, the number of bones in the skull is reduced.
Wolff l. every change in the form and the function of a bone, or in its function alone, is followed by certain definite changes in its internal architecture and secondary alterations in its external conformation; these changes usually represent responses to alterations in weight-bearing stresses.

Lawrence
Lawrence

Robert D., English physician, 1892–1968. See L.-Seip syndrome.

lawrencium
lawrencium (Lr, Lw) (law-ren′se-um)

An artificial transplutonium element; atomic no. 103; atomic wt. 262.11. [E.O. Lawrence, U.S. physicist and Nobel laureate, 1901–1958]

laxation
laxation (lak-sa′shun)

Bowel movement, with or without laxatives. [see laxative]

laxative
laxative (lak′sa-tiv)

1. Mildly cathartic; having the action of loosening the bowels. 2. A mild cathartic; a remedy that moves the bowels slightly without pain or violent action. [L. laxativus, fr. laxo, pp. -atus, to slacken, relax]
diphenylmethane laxatives members of a chemical class of l. agents including phenolphthalein and bisacodyl.

layer
layer (la′er) [TA]

A sheet of one substance lying on another and distinguished from it by a difference in texture or color or by not being continuous with it. SEE ALSO: stratum, lamina. SYN: panniculus.
ameloblastic l. the internal l. of the enamel organ. SYN: enamel l..
anterior elastic l. SYN: anterior limiting l. of cornea.
anterior limiting l. of cornea a transparent homogeneous acellular l., 6 to 9 μm thick, lying between the basal lamina of the outer l. of stratified epithelium and the substantia propria of the cornea; considered to be a basement membrane. SYN: anterior elastic l., Bowman l., Bowman membrane, lamina elastica anterior, lamina limitans anterior corneae.
anterior l. of rectus sheath [TA] the portion of the rectus sheath that lies anterior to the muscle, consisting in its upper two-thirds of contributions from the aponeuroses of the external and internal oblique muscles, and in its lower third (below the arcuate line) of contributions from the aponeuroses of all three muscles of the anterolateral abdominal wall. SYN: lamina anterior vaginae musculi recti abdominis.
anterior l. of thoracolumbar fascia [TA] fascial membrane extending from transverse processes of lumbar vertebrae. SYN: lamina anterior fasciae thoracolumbalis [TA] , fascia musculi quadrati lumborum&star, lamina profunda fasciae thoracolumbalis&star, quadratus lumborum fascia&star.
bacillary l. SYN: l. of rods and cones.
basal l. SYN: stratum basale (1) .
basal cell l. SYN: stratum basale epidermidis.
basal l. of choroid [TA] SYN: lamina basalis choroideae.
basal l. of ciliary body SYN: basal lamina of ciliary body.
l. of Bechterew SYN: band of Kaes-Bechterew.
blastodermic layers the primordial cell layers on the yolk surface of a telolecithal egg; in the earliest stages they consist of protoderm, and then later differentiate into ectoderm, endoderm, and mesoderm.
Bowman l. SYN: anterior limiting l. of cornea.
brown l. SYN: suprachoroid lamina of sclera.
cambium l. 1. the inner osteogenic l. of the periosteum; 2. a highly cellular zone immediately beneath the epithelium covering a botryoid sarcoma.
layers of cerebellar cortex cerebellar cortex.
layers of cerebral cortex cerebral cortex.
cerebral l. of retina the internal l. of the retina containing the neural elements, as distinguished from the outer leaf of the retina, or pigmented l.. SYN: pars optica retinae [TA] , neural l. of retina, stratum cerebrale retinae.
Chievitz l. in the developing retina of an embryo, a transitory zone between the inner and outer neuroblastic layers that is devoid of nuclei.
choriocapillary l. SYN: capillary lamina of choroid.
circular l. of detrusor (muscle) of urinary bladder [TA] the substantial middle l. of three ill-defined, interlacing layers (the inner and outer layers being predominantly longitudinally oriented) of smooth (involuntary) muscle fibers constituting the muscle l. of the wall of the bladder. SYN: stratum circulare musculi detrusoris vesicae [TA] .
circular l. of muscle coat of small intestine [TA] the inner l. of smooth (involuntary) muscle of the muscle coat (muscularis externa) of the small intestine in which the muscle fibers encircle the lumen; it is claimed by some investigators that the orientation of the muscle fibers is a tight spiral or helix rather than being truly circular. SYN: stratum circulare tunicae muscularis intestini tenuis [TA] , short pitch helicoidal l.&star, stratum helicoidale brevis gradus&star.
circular l. of muscular coat [TA] the inner, circular l. of the smooth muscle of the muscular coat. Terminologia Anatomica lists circular layers of muscular coats (stratum circulare tunicae muscularis ...) of the following: 1) colon (... coli [TA]); 2) prostatic urethra (... urethrae prostaticae [TA]); 3) rectum (... recti [TA]); 4) small intestine (... intestini tenuis [TA]); 5) stomach (... gastricae [TA]); 6) urethra (... urethrae [TA]). SYN: stratum circulare tunicae muscularis [TA] .
circular layers of muscular tunics circular l. of muscular coat.
circular l. of tympanic membrane SYN: stratum circulare membranae tympani.
claustral l. the l. of subcortical gray matter between the external capsule and the white matter of the insula or extreme capsule.
clear l. of epidermis SYN: stratum lucidum.
columnar l. SYN: stratum basale epidermidis.
conjunctival l. of bulb SYN: bulbar conjunctiva.
conjunctival l. of eyelids SYN: palpebral conjunctiva.
corneal l. of epidermis SYN: stratum corneum epidermidis.
cornified l. of nail SYN: stratum corneum unguis.
cutaneous l. of tympanic membrane SYN: stratum cutaneum membranae tympani.
deep l. [TA] in a stratified structure, the stratum which lies beneath all others, furthest from the surface. See deep l. of levator palpebrae superioris, deep l. of temporal fascia. SYN: lamina profunda [TA] , deep lamina.
deep gray l. of superior colliculus [TA] a l. of cell bodies in the superior colliculus located between the intermediate white l. and the deep white l.. SYN: stratum griseum profundum colliculis superioris [TA] .
deep l. of levator palpebrae superioris the deeper fibers of the levator muscle of the superior eyelid that are inserted into the superior tarsal plate. SYN: lamina profunda musculi levatoris palpebrae superioris.
deep l. of temporal fascia the deep part of the temporal fascia attaching to the medial surface of the zygomatic arch. SYN: lamina profunda fasciae temporalis [TA] .
deep white l. of superior colliculus a l. of neuron cell bodies in the superior colliculus located between the deep white l. and the intermediate white matter. SYN: stratum medullare profundum [TA] .
deep white l. [TA] of superior colliculus [TA] the innermost l. of the superior colliculus; a l. of myelinated fibers located internal to the deep gray l..
layers of dentate gyrus [TA] from the surface of the dentate gyrus, these layers are: the molecular l. [TA] (stratum moleculare [TA]), which contains dendrites of granular cells and some incoming axons from the perforant pathway, granular l. [TA] (stratum granulare [TA]), which contains the l. of small granular cells, and the multiform l. [TA] (stratum multiforme [TA]), also sometimes called the polymorphic l., which contains axons of granular cells and some afferent axons entering via the fornix. SYN: strata gyri dentati [TA] .
elastic layers of arteries SYN: elastic laminae of arteries, under lamina.
elastic layers of cornea anterior limiting l. of cornea, posterior limiting l. of cornea.
enamel l. SYN: ameloblastic l..
ependymal l. an inner epithelial l. of cells bordering the lumen of the embryonic neural tube and brain, formed during the latter's stratification, and persisting in modified form throughout life. SYN: ependymal zone, ventricular l..
episcleral l. of fibrous l. of eyeball [TA] the delicate moveable l. of loose connective tissue between the external surface of the sclera and the fascial sheath of the eyeball. SYN: lamina episcleralis [TA] , episcleral lamina.
epithelial layers epithelium.
epithelial choroid l. SYN: epithelial lamina.
epitrichial l. the superficial flattened-cell l. of the epidermis of a young embryo before the definitive stratification has developed.
external nuclear l. of retina SYN: neuroepithelial l. of retina.
fatty l. of subcutaneous tissue [TA] superficial portion of the subcutaneous tissue of certain areas of the body (e.g., inferior portion of anterior abdominal wall) which is specialized for fat storage and thus often has an abundance of fat, especially in the overnourished individual, compared with the deeper, fibrous portion of the subcutaneous tissue; in morbid obesity, this l. forms the core of a large, sagging apronlike fold. SEE ALSO: fatty l. of subcutaneous tissue of abdomen. SYN: panniculus adiposus [TA] .
fatty l. of subcutaneous tissue of abdomen [TA] the more superficial, fatty part of the superficial fascia of the lower anterior abdominal wall. SYN: panniculus adiposus telae subcutaneae abdominis [TA] , Camper fascia, fatty l. of superficial fascia.
fatty l. of superficial fascia SYN: fatty l. of subcutaneous tissue of abdomen.
fibromusculocartilagenous l. of bronchi [TA] l. between submucosa and adventitia of bronchi which includes cartilages enclosed in perichondrium continuous between cartilages with a dense, fibrous membrane that includes smooth muscle and elastic fibers; this l. provides rigidity to the wall while allowing active reduction and passive increase in diameter of the bronchus. SYN: tunica fibromusculocartilaginea bronchi [TA] .
fibrous l. the outer dense connective tissue l. of the periosteum.
fibrous l. of eyeball [TA] the outer l. of the eyeball composed of the sclera and cornea. SYN: tunica fibrosa bulbi [TA] , fibrous tunic of eye, tunica externa oculi.
fibrous l. of joint capsule [TA] the outer fibrous part of the capsule of a synovial joint, which may in places be thickened to form capsular ligaments. SYN: membrana fibrosa capsulae articularis [TA] , fibrous l. of articular capsule&star, fibrous membrane of joint capsule&star, fibrous articular capsule, stratum fibrosum capsulae articularis.
fibrous l. in or on deep aspect of fatty l. of subcutaneous tissue [TA] fibrous tissue interspersed within or concentrated in the deeper portions of the otherwise fatty l. of subcutaneous tissue in a particular region, making it more substantial, but not organized into a uniform, membranous l.. SYN: stratum fibrosum panniculi adiposi telae subcutaneae [TA] .
fillet l. SYN: stratum lemnisci.
fusiform l. SYN: multiform l. [TA] of cerebral cortex.
ganglionic l. [TA] the l. of the retina containing primarily the cell bodies of ganglion cells, although some amacrine cell bodies are also found. SEE ALSO: ganglion cells of retina, under cell. SYN: stratum ganglionicum [TA] , ganglionic cell l. of retina.
ganglionic cell l. of retina SYN: ganglionic l..
ganglionic l. of cerebellar cortex SYN: Purkinje cell l..
ganglionic l. of cerebral cortex l. 5 of the cortex cerebri.
ganglionic l. of optic nerve obsolete term used to describe the multipolar neurons in the retina that give rise to the fibers of the optic nerve. SYN: stratum ganglionare nervi optici.
germ l. one of the three primordial cell layers (ectoderm, endoderm, mesoderm) established in an embryo during gastrulation.
germinative l. SYN: stratum basale epidermidis.
germinative l. of nail SYN: stratum germinativum unguis.
glomerular l. of olfactory bulb a l. composed of spherical bodies, called glomeruli, formed by the synapses of mitral cells with the olfactory nerve fibers derived from the cells of the olfactory epithelium.
granular l. [TA] See layers of dentate gyrus. SYN: stratum granulare [TA] .
granular l. of cerebellar cortex [TA] SYN: granular l. of cerebellum.
granular l. of cerebellum [TA] the deepest of the three layers of the cortex; it contains large numbers of granule cells, the dendrites of which synapse with incoming mossy fibers in cerebellar glomeruli. Thin, unmyelinated axons of granule cells ascend perpendicularly into the molecular l. in which they bifurcate into fibers coursing parallel to the long axis of the cerebellar folia. Parallel fibers form numerous synapses with the dendrites of Purkinje cells, basket cells, and stellate cells. SYN: granular l. of cerebellar cortex [TA] , stratum granulosum corticis cerebelli [TA] .
granular layers of cerebral cortex layers 2 (outer) and 4 (inner) of the cortex cerebri.
granular l. of epidermis a l. of somewhat flattened cells containing basophilic granules of keratohyalin and lying just above the stratum spinosum and deep to the stratum corneum. SYN: stratum granulosum epidermidis.
granular l. of a vesicular ovarian follicle SYN: stratum granulosum folliculi ovarici vesiculosi.
gray layers of superior colliculus term applied to any one of the three major layers of gray matter of the superior colliculus that alternate with layers composed chiefly of nerve fibers: 1) the superficial gray l. of superior colliculus, external to the largely white l. of the incoming fibers of the optic tract (optic l.); 2) the intermediate gray l. of superior colliculus, placed between the optic l. and a more deeply located l. of fibers, the stratum lemnisci; 3) the deep gray l. of superior colliculus, between the stratum lemnisci and the central gray substance surrounding the cerebral aqueduct, and containing the large nerve cells from which most of the colliculus descending connections (tectobulbar, tectopontine, and tectospinal tract) originate. SYN: stratum cinereum colliculi superioris, stratum griseum colliculi superioris.
half-value l. (HVL) the thickness of a specific absorber ( e.g., aluminum) that will reduce the intensity of a beam of radiation to one-half its initial value.
Henle l. the outer l. cells of the inner root sheath of the hair follicle.
Henle fiber l. the l. of inner cone fibers in the central area of the retina.
Henle nervous l. SYN: entoretina.
layers of hippocampus [TA] four layers formed by cells and cell processes; they are, beginning at the alveus and ventricular surface: the oriens l. [TA] (stratum oriens [TA]) which contains basal dendrites and axon collaterals of the pyramidal cells, pyramidal l. [TA] (stratum pyramidale [TA]) which contains the sonata of the large pyramidal cells of the hippocampus, radiant l. [TA] (stratum radiatum [TA]) which contain the branching dendrites of the pyramidal cells and recurrent axon collaterals of the pyramidal cells, and the lacunar-molecular l. [TA] (stratum moleculare et substratum lacunosum [TA]) which contains the distal dendrites and some of the incoming axons of the preforant pathway. SYN: strata hippocampi [TA] .
horny l. of epidermis SYN: stratum corneum epidermidis.
horny l. of nail SYN: stratum corneum unguis.
Huxley l. a l. of cells interposed between Henle l. and the cuticle of the inner root sheath of the hair follicle. SYN: Huxley membrane, Huxley sheath.
infragranular l. the cellular band deep to the inner granular l. of the developing human cerebral cortex, which differentiates into the ganglionic l. and multiform l. by the sixth fetal month.
inner l. of eyeball [TA] the third and deepest of the three layers of the eyeball, composed of the retina, intraocular part of the optic nerve, and the retinal blood vessels. SYN: tunica interna bulbi [TA] , nervous tunic of eyeball.
inner limiting l. [TA] the membranelike structure located immediately internal to the l. of nerve fibers; composed of the processes of the neuroglial cells (Müller cells) of the retina. SYN: stratum limitans internum [TA] .
inner nuclear l. [TA] the l. of the retina composed of the cell bodies of bipolar cells, horizontal cells, and some of the cell bodies of amacrine cells. SYN: stratum nucleare internum [TA] .
l. of inner and outer segments [TA] the l. of the retina located external to the outer limiting membrane and composed of the inner and outer segments of the rods and cones; the outer tips of the rod and cone segments are apposed to the pigmented l.. SYN: stratum segmentorum externorum et internorum [TA] .
inner plexiform l. [TA] the l. of the retina composed of the processes of bipolar cells, ganglion cells, and amacrine cells; a l. containing synaptic contacts. SYN: stratum plexiforme internum [TA] .
intermediate l. SYN: mantle l..
intermediate white l. [TA] of superior colliculus [TA] a l. of myelinated fibers located between the intermediate and deep gray layers of the superior colliculus. SYN: stratum medullare intermedium [TA] .
investing l. [TA] a fascial l. that ensheathes or intimately encloses a specific group of muscles. SYN: fascia investiens [TA] .
investing l. of cervical fascia [TA] the part of the cervical fascia investing the sternocleidomastoid and trapezius muscles and completely encircling the neck. SYN: lamina superficialis fasciae cervicalis [TA] , superficial l. of deep cervical fascia&star, investing fascia.
Kölliker l. the l. of connective tissue in the iris.
lacunar-molecular l. [TA] See layers of hippocampus. SYN: stratum moleculare et substratum lacunosum [TA] .
Langhans l. SYN: cytotrophoblast.
latticed l. a cortical cell l. in the hippocampus.
limiting layers of cornea See anterior limiting l. of cornea, posterior limiting lamina of cornea.
longitudinal l. of muscle coat of small intestine [TA] longitudinal l. of muscular coat of small intestine. SYN: stratum longitudinale tunicae muscularis intestini tenuis [TA] , stratum helicoidale longi gradus&star.
longitudinal l. of muscular coat [TA] the outer, longitudinal l. of the smooth muscle of the muscular coat. Terminologia Anatomica lists longitudinal layers of muscular coats (stratum longitudinale tunicae muscularis ...) of the following: 1) intermediate urethra (... urethrae intermediae [TA]); 2) colon (... coli [TA]); 3) prostatic uretra (... urethrae prostaticae [TA]); 4) rectum (... recti [TA]); 5) small intestine (... intestini tenuis [TA]); 6) spongy urethra (... urethrae spongiosae [TA]); 7) stomach (... gastricae [TA]). SYN: stratum longitudinale tunicae muscularis [TA] .
longitudinal layers of muscular tunics longitudinal l. of muscular coat.
long pitch helicoidal l.
malpighian l. SYN: malpighian stratum.
mantle l. the nuclear zone of the developing neural tube between the marginal l. and the ependymal l.; forms the gray matter of the central nervous system. SYN: intermediate l., mantle zone (1) .
marginal l. the outer, nonnuclear l. of the embryonic neural tube; into its fibrous network grow the longitudinal nerve fibers that eventually become the white matter of the spinal cord and brainstem. SYN: marginal zone (2) .
medullary layers of thalamus SYN: medullary laminae of thalamus, under lamina.
membranous l. SYN: membranous lamina of cartilage of pharyngotympanic (auditory) plate.
membranous l. of subcutaneous tissue of abdomen [TA] the deeper, membranous or lamellar part of the subcutaneous tissue of the lower abdominal wall; it is continuous with the superficial perineal (Colles) fascia. SYN: membranous l. of superficial fascia of perineum (2) , membranous l. of superficial fascia (2) , Scarpa fascia.
membranous l. of superficial fascia 1. SYN: subcutaneous tissue of perineum. 2. SYN: membranous l. of subcutaneous tissue of abdomen.
membranous l. of superficial fascia of perineum 1. SYN: subcutaneous tissue of perineum. 2. SYN: membranous l. of subcutaneous tissue of abdomen.
meningeal l. of dura mater cranial dura mater.
Meynert l. SYN: pyramidal cell l..
middle gray l. of superior colliculus gray layers of superior colliculus.
molecular l. term applied to any l. of brain tissue that contains few nerve-cell bodies and is composed largely of terminal arborizations of dendrites and axons; notable examples are the superficial l. (first l.) of the cerebral cortex and the molecular l. of cerebellum. SYN: plexiform l., stratum moleculare.
molecular l. of cerebellar cortex [TA] the outer lamina of the cortex, containing the cell bodies (unless the Purkinje cell l. is designated as a separate l.) and dendrites of Purkinje cells, the axons of the granule cells, and the cell bodies, dendrites, and axons of basket cells. SYN: stratum moleculare corticis cerebelli [TA] , molecular l. of cerebellum.
molecular l. of cerebellum SYN: molecular l. of cerebellar cortex.
molecular l. of cerebral cortex [TA] l. 1 of the cortex cerebri. SYN: lamina molecularis corticis cerebri [TA] , plexiform l. of cerebral cortex.
molecular layers of olfactory bulb the layers, composed mainly of nerve fibers, on the outer and inner sides of the l. of mitral cells of the bulb.
molecular l. of retina name applied to each of the plexiform layers of the retina. SYN: stratum moleculare retinae.
multiform l. [TA] See layers of dentate gyrus. SYN: stratum multiforme [TA] .
multiform l. [TA] of cerebral cortex the innermost l. of the cerebral cortex, l. XI. SYN: fusiform l., polymorphous l., spindle-celled l..
muscle l. in fatty l. of subcutaneous tissue [TA] l. of smooth or striated muscle embedded within the fatty subcutaneous tissue for contraction or to produce movement of the skin, e.g., facial muscles within subcutaneous tissue of face and neck, dartos muscle within the dartos fascia of scrotum. SYN: stratum musculosum panniculi adiposi telae subcutaneae [TA] .
muscular l. [TA] the muscular, usually middle, l. of a tubular structure; for most of the gastrointestinal tract, it consists of an outer longitudinal l. of muscle and an inner circular l.. SYN: tunica muscularis [TA] , muscular coat&star.
muscular l. of bronchi muscular l. of the bronchial wall. SYN: tunica muscularis bronchiorum [TA] , muscular coat of bronchi&star.
muscular l. of colon [TA] muscular l. of the wall of the colon. SYN: tunica muscularis coli [TA] , muscular coat of colon&star.
muscular l. of ductus deferens [TA] muscular l. of the wall of the ductus deferens. SYN: tunica muscularis ductus deferentis [TA] , muscular coat of ductus deferens&star.
muscular l. of esophagus [TA] muscular l. of the esophageal wall. SYN: tunica muscularis esophagi [TA] , muscular coat of esophagus&star.
muscular l. of female urethra [TA] muscular l. of the wall of the female urethra. SYN: tunica muscularis urethrae femininae [TA] , muscular coat of female urethra&star.
muscular l. of gallbladder muscular tunic of the gallbladder, consisting of layers of smooth muscle fibers coursing in various directions immediately external to the mucosa of the gallbladder. SYN: tunica muscularis vesicae biliaris [TA] , muscular coat of gallbladder&star, tunica muscularis vesicae felleae&star, muscular tunic of gallbladder.
muscular l. of intermediate part of (male) urethra [TA] relatively thin inner coat of smooth (involuntary) muscle bundles, mostly longitudinally arranged and separated from the epithelium by a thin vascular stroma of fibroelastic connective tissue, which are continuous superiorly with those of the prostatic urethra and peripherally with an outer, much more prominent l. of circularly oriented skeletal (voluntary) muscle fibers that forms the main, tubelike part of the external urethral sphincter. SEE ALSO: external urethral sphincter of male. SYN: tunica muscularis partis intermediae urethrae masculinae [TA] , muscular coat of intermediate part of male urethra&star.
muscular l. of large intestine [TA] muscular l. of the wall of all parts of the large intestine (cecum, colon, rectum, and anal canal) collectively. SYN: tunica muscularis intestini crassi [TA] , muscular coat of large intestine&star.
muscular l. of male urethra [TA] muscular l. of the prostatic, intermediate, and spongy segments of the male urethra. SEE ALSO: muscular l. of intermediate part of (male) urethra. SYN: tunica muscularis urethrae masculinae [TA] , muscular coat of male urethra.
muscular l. of mucosa SYN: muscularis mucosae.
muscular l. of pharynx [TA] muscular l. of the pharyngeal wall. In contrast with the muscular coats of the rest of the gastrointestinal tract (except anal canal), that of the pharynx has an outer circular l. and an inner longitudinal l.. SYN: tunica muscularis pharyngis [TA] , muscular coat of pharynx&star.
muscular l. of prostatic urethra [TA] relatively thin inner coat of smooth (involuntary) muscle bundles, both circularly and longitudinally arranged and separated from the epithelium by a thin vascular stroma of fibroelastic connective tissue, which are continuous inferiorly with those of the intermediate urethra and peripherally with the fibromuscular tissue of the prostate, including a relatively thick, troughlike l. of skeletal (voluntary) muscle that ascends the anterior aspect of the prostatic urethra to the neck of the bladder as part of the external urethral sphincter; proximal (superior) to the seminal colliculus, which bears the openings of the ejaculatory ducts, the circular l. of smooth muscle is especially prominent as a continuation of the internal urethral sphincter of the intramural or preprostatic part of the urethra. SEE ALSO: external urethral sphincter of male, internal urethral sphincter. SYN: tunica muscularis partis prostaticae urethrae masculinae [TA] , muscular coat of intermediate part of male urethra&star, muscular coat of prostatic urethra.
muscular l. of rectum [TA] muscular l. of the wall of the rectum. SYN: tunica muscularis recti [TA] , muscular coat of rectum&star.
muscular l. of renal pelvis [TA] middle l. (between outer adventitia and inner mucosa) composed of two morphologically and histochemically distinct types of smooth (involuntary) muscle fibers, one of which is identical and continuous with that of the ureters, while the other is unique to the calices and pelvis. SYN: tunica muscularis pelvis renalis [TA] .
muscular l. of seminal gland [TA] middle l. (between outer connective tissue and inner mucosa) of the seminal gland wall, composed of outer longitudinal and inner circular layers of smooth muscle. SYN: tunica muscularis glandulae vesiculosae [TA] .
muscular l. of small intestine [TA] muscular l. of the wall of the small intestine. SYN: tunica muscularis intestini tenuis [TA] , muscular coat of small intestine&star.
muscular l. of spongy (male) urethra [TA] relatively sparse l. of mostly longitudinally disposed smooth (involuntary) muscle fibers between the mucosa and the surrounding erectile tissue of the corpus spongiosum penis. SYN: tunica muscularis partis spongiosae urethrae masculinae [TA] , muscular coat of spongy part of male urethra&star.
muscular l. of stomach [TA] muscular tunic of the stomach, consisting of smooth muscles arranged in three fairly well-defined layers: an outer longitudinal l., continuous with that of the esophagus but dividing at the cardia into two bands which run along the greater and lesser curvatures, leaving the middle areas of the anterior and posterior walls devoid of longitudinal fibers, and then coalescing in the pyloric region into a complete l. which is continuous with the longitudinal coat of the duodenum. The middle circular l. is most complete and strongest, continuous with the circular l. of the esophagus at the cardia; it thickens progressively toward the pylorus, ultimately forming the muscular ring of the pyloric sphincter. The inner, oblique l. is unique to the stomach and is most strongly developed in the fundic region and absent along the lesser curvature. This absence contributes to the formation of the “gastric canal.” SYN: tunica muscularis gastrica [TA] , muscular coat of stomach&star, tunica muscularis ventriculi.
muscular l. of trachea [TA] muscular l. of the tracheal wall. SYN: tunica muscularis tracheae [TA] , muscular coat of trachea&star.
muscular l. of ureter [TA] muscular l. of the ureteric wall. SYN: tunica muscularis ureteris [TA] , muscular coat of ureter&star.
muscular l. of urinary bladder [TA] muscular l. of the wall of the urinary bladder. SYN: tunica muscularis vesicae urinariae [TA] , muscular coat of urinary bladder&star.
muscular l. of uterine tube [TA] muscular l. of the wall of the uterine tube. SYN: tunica muscularis tubae uterinae [TA] , muscular coat of uterine tube&star.
muscular l. of vagina [TA] muscular l. of the vaginal wall. SYN: tunica muscularis vaginae [TA] , muscular coat of vagina&star.
l. of nerve fibers [TA] the l. of the retina composed of the axonal processes of the ganglion cells; these processes converge to form the optic nerve. SYN: stratum neurofibrarum [TA] .
neural l. of optic part of retina retina.
neural l. of retina SYN: cerebral l. of retina.
neuroepithelial l. of retina the outermost l. of the cerebral l. of retina, composed of the primary receptor cells of the retina; this area consists of two layers: 1) a l. of inner and outer segments [TA] made up of the rods and cones, the photosensitive processes of the receptor cells, and 2) the outer nuclear l. [TA] containing the cell bodies of these cells; the outer limiting membrane (outer limiting l. [TA]) forms a perforated supporting plate between the two sublayers; the name refers to the fact that the retinal receptor cells are a specialized form of (epithelial) ependyma cell and thus, in a sense, are comparable to the neuroepithelial cells ( e.g., hair cells) of other sense organs. SYN: external nuclear l. of retina, stratum neuroepitheliale retinae.
Nitabuch l. SYN: Nitabuch membrane.
nuclear layers of retina the outer nuclear l., l. 4, of the retina, neuroepithelial l. of retina, and the inner l., l. 6, of the retina, ganglionic l. of retina. SYN: strata nuclearia externa et interna retinae.
odontoblastic l. a l. of mesenchymal cells at the periphery of the dental pulp of the tooth.
optic l. [TA] 1. a l. of white matter interspersed with nerve-cell bodies, immediately below the superficial gray l. of the superior colliculus, composed of myelinated fibers originating in the retina and striate cortex; 2. a rarely used term to describe the inner l. of the retina, consisting of the fibers originating from the cells of the ganglionic l. of the retina; in their further course these fibers combine to form the optic nerve. SYN: stratum opticum [TA] .
orbital l. of ethmoid bone SYN: orbital plate of ethmoid bone.
oriens l. [TA] See layers of hippocampus. SYN: stratum oriens [TA] .
osteogenetic l. the inner bone-forming l. of the periosteum.
outer limiting l. [TA] the membranelike structure located immediately internal to the l. of inner and outer segments; made up of processes of the neuroglial cells of the retina (Müller cells); penetrated by the portion of the rods and cones located between the inner and outer segments and the cell body. SYN: stratum limitans externum [TA] .
outer nuclear l. [TA] the l. of the retina containing the cell bodies of the rods and cones. SYN: stratum nucleare externum [TA] .
outer plexiform l. [TA] the l. of the retina composed of the processes of rods and cones, horizontal cells, and bipolar cells; a l. containing synaptic contacts. SYN: stratum plexiforme externum [TA] .
palisade l. SYN: stratum basale epidermidis.
papillary l. SYN: stratum papillare corii.
parietal l. [TA] the outer l. of an enveloping sac or bursa, usually lining the walls of the cavity or space occupied by the enveloped structure, the structure itself being covered with the inner or visceral l. of the enveloping sac; an actual or potential space is enclosed by the two continuous layers, intervening between parietal and visceral layers. The parietal l. is usually the more substantial l.. SYN: lamina parietalis [TA] .
parietal l. of leptomeninges SYN: arachnoid mater.
parietal l. of serous pericardium [TA] the outer part of the serous pericardium suported by the fibrous pericardium. SYN: lamina parietalis pericardii serosi [TA] .
parietal l. of tunica vaginalis of testis [TA] the outer part of the tunica vaginalis testis supported by the internal spermatic fascia. SYN: lamina parietalis tunicae vaginalis testis [TA] .
perforated l. of sclera SYN: lamina cribrosa of sclera.
periosteal l. of dura mater cranial dura mater.
pigmented l. of ciliary body SYN: stratum pigmenti corporis ciliaris.
pigmented l. of iris SYN: stratum pigmenti iridis.
pigmented l. of retina [TA] the outer l. of the retina, consisting of pigmented epithelium. SYN: ectoretina, stratum pigmenti bulbi, stratum pigmenti retinae, tapetum nigrum, tapetum oculi.
piriform neuron l. an obsolete term for the Purkinje cell l..
l. of piriform neurons SYN: Purkinje cell l..
plasma l. SYN: still l..
plexiform l. SYN: molecular l..
plexiform l. of cerebral cortex SYN: molecular l. of cerebral cortex.
plexiform layers of retina layers of the retina where synapses occur; in the external l., processes of rods and cones synapse with bipolar neuron dendrites; in the internal l., axon terminals of bipolar cells synapse with ganglion cell dendrites. See retina. SYN: stratum plexiforme internum [TA] , stratum plexiforme externum.
polymorphous l. SYN: multiform l. [TA] of cerebral cortex.
posterior elastic l. SYN: posterior limiting lamina of cornea.
posterior limiting l. of cornea SYN: posterior limiting lamina of cornea.
posterior l. of rectus sheath [TA] the portion of the sheath of the rectus abdominis muscle that lies posterior to the muscle covering only its upper two-thirds; it is formed by contributions from the aponeuroses of the internal oblique and transversus abdominis muscles; its free inferior margin forms the arcuate line; it is deficient below this, the posterior aspect of the muscle being covered only by transversalis fascia and peritoneum. SYN: lamina posterior vaginae musculi recti abdominis [TA] .
pretracheal l. of cervical fascia [TA] the l. of fascia investing the infrahyoid muscles and contributing to the formation of the carotid sheath. SYN: lamina pretrachealis fasciae cervicalis [TA] , middle cervical fascia, Porter fascia, pretracheal fascia.
prevertebral l. of cervical fascia [TA] the part of the cervical fascia that covers the bodies of the cervical vertebrae and the muscles attaching to them and to the anterior parts of their transverse processes. SYN: lamina prevertebralis fasciae cervicalis [TA] , prevertebral fascia.
prickle cell l. SYN: stratum spinosum epidermidis.
Purkinje cell l. the l. of large neuron cell bodies located at the interface of molecular and granular layers in the cerebellar cortex; dendrites of these cells fan outward into the molecular l. in a plane transverse to the folium. SYN: stratum purkinjense corticis cerebelli [TA] , ganglionic l. of cerebellar cortex, l. of piriform neurons, Purkinje cells, Purkinje corpuscles.
pyramidal l. [TA] See layers of hippocampus. SYN: stratum pyramidale [TA] .
pyramidal cell l. layers 3 and 5 of the cortex cerebri. SYN: Meynert l..
radiant l. [TA] See layers of hippocampus. SYN: stratum radiatum [TA] .
radiate l. of tympanic membrane SYN: stratum radiatum membranae tympani.
Rauber l. 1. the thinned-out trophoblastic membrane over the embryonic disk in developing carnivores and ungulates; 2. outermost cell l. which helps form the blastodisk; called blastodermic or primitive ectoderm.
reticular l. of corium SYN: stratum reticulare corii.
layers of retina retina.
l. of rods and cones the l. of the retina next to the pigment l. and containing the visual receptors. SEE ALSO: retina, neuroepithelial l. of retina. SYN: bacillary l..
rostral l. SYN: rostral lamina.
Sattler elastic l. the middle l. of the choroid.
serous l. of peritoneum SYN: serosa of peritoneum.
short pitch helicoidal l. circular l. of muscle coat of small intestine.
layers of skin See epidermis, dermis.
sluggish l. SYN: still l..
somatic l. the external l. of the lateral mesoderm of the embryo, lying adjacent to the ectoderm and together with it constituting the somatopleure.
spindle-celled l. SYN: multiform l. [TA] of cerebral cortex.
spinous l. SYN: stratum spinosum epidermidis.
splanchnic l. the internal l. of the lateral mesoderm, lying adjacent to the endoderm and together with it forming the splanchnopleure.
spongy l. of female urethra [TA] inappropriate reference to the lamina propria of the mucous membrane of the female urethra, characterized by numerous, thin-walled veins that have in the past been falsely compared with erectile tissue. SYN: tunica spongiosa urethrae femininae [TA] .
spongy l. of vagina [TA] inappropriate collective reference to the abundant venous plexuses of the vagina, occurring within the mucosal and muscular layers (giving the rugae somewhat the character of erectile tissue) as well as in the adventitia (the laterally placed vaginal venous plexuses), falsely suggesting a discrete l. of erectile tissue. SYN: tunica spongiosa vaginae [TA] .
still l. the l. of the bloodstream in the capillary vessels, next to the wall of the vessel, that flows slowly and transports the white blood cells along the l. wall, while in the center the flow is rapid and transports the red blood cells. SYN: plasma l., Poiseuille space, sluggish l..
subendocardial l. the loose connective tissue l. that joins the endocardium and myocardium; in the ventricles, it contains branches of the conducting system of the heart.
subendothelial l. the thin l. of connective tissue lying between the endothelium and elastic lamina in the intima of blood vessels.
subpapillary l. the vascular l. of the corium.
subserous l. subserosa.
superficial l. [TA] in a stratified structure, the outermost or topmost of the strata; the stratum nearest the surface. See superficial l. of deep cervical fascia, superficial l. of the levator palpebrae superioris, superficial l. of temporal fascia. SYN: lamina superficialis [TA] , superficial lamina.
superficial l. of deep cervical fascia investing l. of cervical fascia.
superficial gray l. [TA] of superior colliculus gray layers of superior colliculus.
superficial l. of the levator palpebrae superioris [TA] the superficial fibers of the levator muscle of the superior eyelid which are inserted into the skin of the superior eyelid. SYN: lamina superficialis musculi levatoris palpebrae superioris.
superficial l. of temporal fascia [TA] the superficial part of the temporal fascia attaching to the lateral surface of the zygomatic arch. SYN: lamina superficialis fasciae temporalis [TA] .
suprachoroid l.
Tomes granular l. a thin l. of dentin adjacent to the cementum, appearing granular in ground sections; the granules are small uncalcified spaces.
vascular l. SYN: vascular lamina of choroid.
vascular l. of choroid coat of eye SYN: vascular lamina of choroid.
vascular l. of eyeball [TA] the vascular, pigmentary, or middle coat of the eye, comprising the choroid, ciliary body, and iris. SYN: tunica vasculosa bulbi [TA] , Haller tunica vasculosa, tunica vasculosa oculi, uvea, uveal tract, vascular tunic of eye.
vascular l. of testis [TA] innermost of three coats (with tunicae vaginalis and albuginea) investing the testis consisting of a vascular plexus in a delicate loose connective tissue matrix that covers the internal aspect of the tunica albuginea and extends deeply, covering the septa and therefore surrounding the lobules of the testis. SYN: tunica vasculosa testis [TA] .
ventricular l. SYN: ependymal l..
visceral l. [TA] the inner l. of an enveloping sac or bursa which lines the outer surface of the enveloped structure, as opposed to the parietal l. which lines the walls of the occupied space or cavity. The visceral l. is usually thin, delicate and not apparent as being separate, but rather appears to be the outer surface of the structure itself. SEE ALSO: serosa. SYN: lamina visceralis [TA] .
visceral l. of serous pericardium [TA] the inner part of the serous pericardium applied directly on the heart. SYN: epicardium&star, lamina visceralis pericardii.
visceral l. of tunica vaginalis of testis [TA] the inner part of the tunica vaginalis testis applied directly to the testis and epididymis. SYN: lamina visceralis tunicae vaginalis testis [TA] .
Waldeyer zonal l. SYN: dorsolateral fasciculus.
Weil basal l. the l. beneath the odontoblasts of the tooth; it contains reticular fibers but few if any cells. SYN: Weil basal zone.
zonular l. 1. a thin l. of white substance covering the upper surface of the thalamus and forming part of the floor of the body of the lateral ventricle; 2. a l. of white substance on the surface of the superior colliculus. SYN: stratum zonale [TA] .

lazaret
lazaret, lazaretto (laz′a-ret, -ret′o)

Obsolete term for: 1. A hospital for the treatment of contagious diseases. 2. A place of detention for persons in quarantine. [It. lazzaretto, fr. lazzaro, a leper]

lb
lb

Abbreviation for pound.

LBF
LBF

Abbreviation for Lactobacillus bulgaricus factor.

LCAT
LCAT

Abbreviation for lecithin-cholesterol acyltransferase.

l-cone
l-cone

Long-wavelength–sensitive cone (red cone).

LD
LD

Abbreviation for lethal dose.

LDH
LDH

Abbreviation for lactate dehydrogenase.

LDL
LDL

Abbreviation for low density lipoprotein. See lipoprotein.

LE
LE, L.E.

Abbreviation for left eye; lupus erythematosus.

leaching
leaching (lech′ing)

1. Removal of the soluble constituents of a substance by running water through it. 2. Solubilization of metals, typically from poor ores, using lithotrophic bacteria. [A.S. leccan, to wet]

lead
lead (Pb) (led)

A metallic element, atomic no. 82, atomic wt. 207.2. SYN: plumbum.
l. acetate has been used as an astringent in diarrhea, and in aqueous solution as a wet dressing in certain dermatoses. SYN: sugar of l..
black l. SYN: graphite.
l. carbonate a heavy white powder that is insoluble in water; occasionally, it is used to relieve irritation in dermatitis, but it is used largely in the manufacture of paint and in the arts and is thus productive of l. poisoning. SYN: ceruse, white l..
l. chromate SYN: chrome yellow.
l. monoxide has been used as an ingredient in external applications such as l. plaster. SYN: l. oxide (yellow), litharge, massicot.
l. oxide (yellow) SYN: l. monoxide.
red l. SYN: l. tetroxide.
red oxide of l. SYN: l. tetroxide.
l. sulfide PbS;the native form in which l. is chiefly found. SYN: galena.
l. tetraethyl SYN: tetraethyllead.
l. tetroxide a bright orange-red powder that turns black when heated; used in ointments and plasters. SYN: red l., red oxide of l..
white l. SYN: l. carbonate.

lead
lead₁ (led)

An electrocardiographic cable with connections within the electronics of the machine designated for an electrode placed at a particular point on the body surface.
ABC leads the leads for recording one kind of vectorcardiogram utilizing the Arrighi triangle; supplanted by XYZ leads.
augmented l. electrocardiogram recorded between one limb and two other limbs. The augmented leads are designated aVF, aVL, and aVR for recordings made between the foot (left), left arm, and right arm, respectively, and the other two limbs.
bipolar l. a record obtained with two electrodes placed on different regions of the body, each electrode contributing significantly to the record; e.g., a standard limb l..
CB l. a bipolar chest l. with the negative electrode placed upon the subject's back.
CF l. a bipolar chest l. with the negative electrode placed on the subject's left leg.
chest leads those in which the exploring electrode is on the chest overlying the heart or its vicinity. SYN: precordial leads, semidirect leads.
CL l. a bipolar chest l. with the negative electrode placed on the subject's left arm.
CR l. a bipolar chest l. with the negative electrode placed on the subject's right arm.
direct l. in electrocardiography, a unipolar l. recorded with the exploring electrode placed directly on the surface of the exposed heart.
esophageal l. an electrocardiographic l. passed down the throat into the esophagus to record the electrocardiogram at various levels of the esophagus; especially useful for certain types of arrhythmias. Similarly, a transducer for echocardiography can be passed into the esophagus.
indirect l. SYN: standard limb l..
intracardiac l. the record obtained when the exploring electrode is placed within one of the heart's chambers, usually by means of cardiac catheterization.
limb l. one of the three standard leads (leads I, II, III) or one of the unipolar limb leads (aVR, aVL, aVF).
precordial leads SYN: chest leads.
semidirect leads SYN: chest leads.
standard limb l. one of the three original bipolar limb leads of the clinical electrocardiogram, designated I, II, and III: l. I records the potential difference between the right and left arms; l. II the difference between right arm and the leg electrode; and l. III the difference between left arm and the leg electrode. SYN: indirect l..
unipolar leads those in which the exploring electrode is on the chest in the vicinity of the heart or on one of the limbs, while the other or indifferent electrode is the central terminal.
V l. a unipolar l. with the central terminal as the indifferent electrode; V is the symbol for unipolar (Latin “U”).

leaflet
leaflet (lef′let)

1. A layer of phospholipid; thus, a bilayer has two leaflets. 2. A thin flattened object or structure.

League of Red Cross Societies
League of Red Cross Societies

The international federation of national Red Cross and similar societies.

learned helplessness
learned helplessness

A laboratory model of depression involving both classical (respondent) and instrumental (operant) conditioning techniques; application of unavoidable shock is followed by failure to cope in situations where coping might otherwise be possible.

learning
learning (lern′ing)

Generic term for the relatively permanent change in behavior that occurs as a result of practice. SEE ALSO: conditioning, forgetting, memory.
incidental l. l. without a direct attempt. SYN: passive l..
insight l. the grasp of the solution to a problem without the intervening series of the trial and error steps that are associated with most types of l. ( e.g., a monkey housed behind the bars of a cage who, without proceeding through countless hours of futile attempts with one stick or the other, fits two sticks together to retrieve a banana outside the distance measured by either stick alone).
latent l. that l. which is not evident to the observer at the time it occurs, but which is inferred from later performance in which l. is more rapid than would be expected without the earlier experience.
passive l. SYN: incidental l..
rote l. the l. of arbitrary relationships, usually by repetition of the l. procedure through memorization and without an understanding of the relationships.
state-dependent l. l. during a specific state of sleep or wakefulness, or during a chemically altered state, where retrieval of learned information ( e.g., as measured by performance of a learned response) cannot be demonstrated unless the subject is restored to the state that originally existed during l..

least squares
least squares

A principle of estimation invented by Gauss in which the estimates of a set of parameters in a statistical model are the quantities that minimize the sum of squared differences between the observed values of the dependent variable and the values predicted by the model.

Le Bel
Le Bel

Joseph Achille, French chemist, 1847–1930. See L.-van't Hoff rule.

Leber
Leber

Theodor, German ophthalmologist, 1840–1917. See L. idiopathic stellate neuroretinitis, L. hereditary optic atrophy, L. plexus, amaurosis congenita of L..

Le Chatelier
Le Chatelier

Henri, French physical chemist, 1850–1936. See L. law, L. principle.

lecithal
lecithal (les′i-thal)

Having a yolk or pertaining to the yolk of any egg; used especially as a suffix. [G. lekithos, egg yolk]

lecithin
lecithin (les′i-thin)

Traditional term for 1,2-diacyl-sn-glycero-3-phosphocholines or 3-sn-phosphatidylcholines, phospholipids that on hydrolysis yield two fatty acid molecules and a molecule each of glycerophosphoric acid and choline. In some varieties of l., both fatty acids are saturated, others contain only unsaturated acids ( e.g., oleic, linoleic, or arachidonic acid); in others again, one fatty acid is saturated, the other unsaturated. Lecithins are yellowish or brown waxy substances, readily miscible in water, in which they appear under the microscope as irregular elongated particles known as “myelin forms,” and are found in nervous tissue, especially in the myelin sheaths, in egg yolk, and as essential constituents of animal and vegetable cells. [G. lekithos, egg yolk]
l. acyltransferase SYN: l.-cholesterol acyltransferase.
l.-cholesterol transferase a plasma enzyme that catalyzes the uptake of cholesterol esters by intermediate-density lipoproteins formed by high density lipoproteins.

lecithinase
lecithinase (les′i-thi-nas)

SYN: phospholipase.
l. A SYN: phospholipase A₂.
l. B SYN: lysophospholipase.
l. C SYN: phospholipase C.
l. D SYN: phospholipase D.

lecithin-cholesterol acyltransferase
lecithin-cholesterol acyltransferase (LCAT)

An enzyme that reversibly transfers an acyl residue from a lecithin to cholesterol, forming a 1-acylglycerophosphocholine (a lysolecithin) and a cholesteryl ester; a deficiency of this enzyme leads to an accumulation of unesterified cholesterol in plasma resulting in anemia, proteinuria, renal failure, and corneal opacities; LCAT is also low in individuals with fish eye disease. SYN: lecithin acyltransferase.

lecithoblast
lecithoblast (les′i-tho-blast)

One of the cells proliferating to form the yolk-sac endoderm. [G. lekithos, egg yolk, + blastos, germ]

lecithoprotein
lecithoprotein (les′i-tho-pro′ten)

A conjugated protein, with lecithin as the prosthetic group.

Leclef Leclef

See Denys-L. phenomenon.

Leclercia
Leclercia (le-clar′ce-a)

A genus in the family Enterobacteriaceae that resembles the genus Escherichia, but is separable by metabolic and genetic classification. Isolated from the feces of humans and animals, it has been recovered clinically from blood, feces, sputum, urine, and wounds; its degree of pathogenicity is unclear.

lectin
lectin (lek′tin)

Any of a group of glycoproteins of primarily plant (usually seed) origin that binds to glycoproteins on the surface of cells causing agglutination, precipitation, or other phenomena resembling the action of specific antibody; lectins include plant agglutinins (phytoagglutinins, phytohemagglutinins), plant precipitins, and perhaps certain animal proteins; some have mitogenic properties and induce lymphocyte transformation. [L. lego, pp. lectum, to select, + -in]
mitogenic l. a l. that induces the replication of polynucleic acids and the proliferation of lymphocytes.

Ledermann
Ledermann

Sully, French psychiatrist. See L. formula.

ledge
ledge (lej)

In anatomy, a structure resembling a l.. SEE ALSO: shelf, lamina.
dental l. a band of ectodermal cells growing from the epithelium of the embryonic jaws into the underlying mesenchyme; local buds from the l. give rise to the primordia of the enamel organs of the teeth. SYN: dental lamina, dental shelf, dentogingival lamina, enamel l., primary dental lamina.
enamel l. SYN: dental l..

Lee
Lee

Robert, English physician, 1793–1877. See L. ganglion.

Lee
Lee

Roger I., U.S. physician, 1881–1967. See L.-White method.

leech
leech (lech)

1. A bloodsucking aquatic annelid worm (genus Hirudo, class Hirudinea) sometimes used in medicine for local withdrawal of blood.For various l. species, see Hirudo. 2. To treat medically by applying leeches. [A.S. laece, a physician; a l., because of its therapeutic use]

leeching
leeching (lech′ing)

The former practice of applying leeches to the body to draw blood for therapeutic purposes.

Leede
Leede

Carl S., U.S. physician, *1882. See Rumpel-L. sign, Rumpel-L. test, L.-Rumpel phenomenon.

LEEP
LEEP

Abbreviation for loop electrocautery excision procedure; loop electrosurgical excision procedure.

Leeuwenhoek
Leeuwenhoek

Anton van, Dutch microscopist, 1632–1723. See L. canals, under canal.

Lefèvre
Lefèvre

Paul, 20th century French dermatologist. See Papillon-L. syndrome.

Le Fort
Le Fort

Léon C., French surgeon and gynecologist, 1829–1893. See L. I fracture, L. II fracture, L. III fracture, L. sound, L. amputation.

left-footed
left-footed

SYN: sinistropedal.

left-handed
left-handed

Denoting the habitual or more skillful use of the left hand for writing and for most manual operations. SYN: sinistromanual.

left-sidedness
left-sidedness

The normal left-sided location of certain unpaired organs, such as the spleen and most of the stomach.
bilateral left-sidedness a syndrome in which normally unpaired organs develop more symmetrically in mirror image; two spleens, one on each side, are usually present, and cardiovascular anomalies are common. SYN: polysplenia syndrome.

leg
leg

1. [TA] Anatomically, the segment of the lower limb between the knee and the ankle; commonly used to mean the entire inferior limb. 2. A structure resembling a l.. SYN: crus (1) [TA] .
l. of antihelix SYN: crura of antihelix, under crus.
bow-l. See genu varum.
elephant l. SYN: elephantiasis.
restless legs SYN: restless legs syndrome.
rider's l. a strain of the adductor muscles of the thigh.
tennis l. a rupture of the gastrocnemius muscle at the musculotendinous junction, resulting from forcible contractions of the calf muscles; commonly seen in tennis players.

Legal
Legal

Emmo, German physician, 1859–1922. See L. test.

Legendre
Legendre

Gaston J., French physician, *1887. See L. sign.

Legg
Legg

Arthur T., U.S. surgeon, 1874–1939. See L.-Calvé-Perthes disease.

-legia -legia

Reading, as distinguished from the G. derivatives, -lexis and -lexy, which signify speech. [L. lego, to read]

Legionella
Legionella (le-ju-nel′la)

A genus of aerobic, motile, nonacid-fast, nonencapsulated, Gram-negative bacilli (family Legionellaceae) that have a nonfermentative metabolism and require l-cysteine HCl and iron salts for growth; they are water-dwelling, airborne-spread, and pathogenic for humans. Over 40 species have been identified; the type species is L. pneumophila.
L. bozemanii a bacterial species that causes human pneumonia.
L. dumoffii a bacterial species implicated in pneumonia.
L. feeleii a bacterial species implicated in pneumonia.
L. gormanii a bacterial species implicated in pneumonia.
L. longbeachae a bacterial species implicated in pneumonia.
L. micdadei a bacterial species that may be acid-fast, and that causes Pittsburgh pneumonia, a variant of Legionnaires disease. Accounts for approximately 60% of L. pneumonias other than those caused by L. pneumophila. SYN: Pittsburgh pneumonia agent.
L. pneumophila a bacterial species that is the primary etiologic agent of Legionnaires disease; believed to grow in plumbing systems or in standing water in ventilation systems. The type species of the genus L..
L. wadsworthii a bacterial species implicated in pneumonia.

legionellosis
legionellosis (le-ju-nel-o′sis)

SYN: Legionnaires disease.

legumin
legumin (le-goo′min, leg′oo-min)

SYN: avenin.

leguminivorous
leguminivorous (le-goo-mi-niv′o-rus)

Feeding on beans, peas, and other legumes.

Lehmann
Lehmann

J.O. Orla, Swedish physician, *1927. See Börjeson-Forssman-L. syndrome.

Leigh
Leigh

Denis, British psychiatrist, *1915. See L. disease.

Leiner
Leiner

Karl, Austrian pediatrician, 1871–1930. See L. disease.

leio- leio-

Smooth. [G. leios]

leiomyofibroma
leiomyofibroma (li-o-mi′o-fi-bro′ma)

SYN: fibroleiomyoma.

leiomyoma
leiomyoma (li′o-mi-o′ma)

A benign neoplasm derived from smooth (nonstriated) muscle. [leio- + G. mys, muscle, + -oma, tumor]
l. cutis cutaneous eruption of multiple small painful nodules composed of smooth muscle fibers; derived from arrector muscles of hair. Solitary, nonpainful l. cutis may arise from cutaneous blood vessels and genital skin. SYN: dermatomyoma.
parasitic l. a uterine l. which has become detached from the uterus and adherent to another peritoneal surface from which it derives a blood supply.
vascular l. a markedly vascular l., apparently arising from the smooth muscle of blood vessels. SYN: angioleiomyoma, angiomyofibroma, angiomyoma.

leiomyomatosis
leiomyomatosis (li′o-mi′o-ma-to′sis)

The state of having multiple leiomyomas throughout the body.
l. peritonealis disseminata a benign condition characterized by multiple small nodules on abdominal and pelvic peritoneum grossly mimicking disseminated ovarian cancer but with histologic characteristics of benign myoma; often associated with recent pregnancy.

leiomyomectomy
leiomyomectomy (li′o-mi-o-mek′to-me)

Surgical resection of a leiomyoma, usually of the uterus.

leiomyosarcoma
leiomyosarcoma (li′o-mi′o-sar-ko′ma)

A malignant neoplasm derived from smooth (nonstriated) muscle. [leio- + myosarcoma]

leiotrichous
leiotrichous (li-ot′ri-kus)

Having straight hair. [leio- + G. thrix, hair]

leipo- leipo-

See lipo-.

Leipzig yellow
Leipzig yellow [C.I. 77600]

SYN: chrome yellow.

Leishman
Leishman

Sir William B., Scottish surgeon, 1865–1926. See Leishmania, L. chrome cells, under cell, L. stain, L.-Donovan body.

Leishmania
Leishmania (lesh-man′e-a)

A genus of digenetic, asexual, protozoan flagellates (family Trypanosomatidae) that occur as amastigotes in the macrophages of vertebrate hosts, and as promastigotes in invertebrate hosts and in cultures. Species are largely indistinguishable morphologically, but may be separated by clinical manifestations, geographic distribution and epidemiology, developmental patterns of promastigotes in their sandfly hosts, virulence testing of clones in vivo, the effect of test sera on growth in culture, cross-immunity tests, and serotyping with promastigote excreted factors; strains also can be distinguished by various biochemical analyses. Such procedures have identified all of the recognized groups and confirmed the separation of New World leishmaniasis agents into two species complexes, L. mexicana and L. braziliensis. [W. B. Leishman]
L. aethiopica an African species of L. responsible for human cutaneous leishmaniasis in Ethiopia, with a reservoir of human infection in the rock hyraxes, Procavia capensis and Heterohyrax brucei, and in Kenya, with reservoirs in the tree hyrax, Dendrohyrax arboreus, and the giant rat, Cricetomys gambianus; vectors are the sandflies Phlebotomus longipes and P. pedifer. It causes a cutaneous leishmaniasis of three types: classical oriental sore, mucocutaneous leishmaniasis, and diffuse cutaneous leishmaniasis; ulceration is late or absent and healing takes one to three years.
L. braziliensis a species that is the causal agent of mucocutaneous leishmaniasis, endemic in southern Mexico and Central and South America, and transmitted by various species of Lutzomyia (New World sandflies); forest rodents and other neotropical arboreal animals serve as reservoir hosts. L. braziliensis is currently divided into three clinically, epidemiologically, and biochemically distinct strains or subspecies: L. b. braziliensis, L. b. guyanensis, and L. b. panamensis.
L. braziliensis braziliensis the type subspecies of L. braziliensis and the agent of mucocutaneous leishmaniasis. A natural reservoir of infection remains unknown, but the proven vector in Brazil is Lutzomyia (Psychodopygus) wellcomei; other sandflies may also transmit the infection.
L. braziliensis guyanensis a subspecies within the L. braziliensis complex from Brazil and Guyana, and the cause of the cutaneous leishmaniasis condition locally known as “pian bois”; the reservoir host in Brazil is the sloth Choloepus hoffmani and the vector is the sandfly Lutzomyia umbratilis.
L. braziliensis panamensis a subspecies of L. braziliensis found in Panama, Colombia, and neighboring regions; it causes ulcerating lesions of cutaneous leishmaniasis which do not heal spontaneously and often involve nearby lymphatic tissues, but nasopharyngeal involvement is rare. The sloth Choloepus hoffmani is the reservoir in Panama and Costa Rica; the sandfly Lutzomyia trapidoi has been proven to be a vector.
L. donovani a species that is the causal agent of visceral leishmaniasis in Mediterranean and adjacent countries, the south central section of the former USSR, eastern India, northern China, Kenya, Ethiopia, and the Sudan; also found in Brazil, Argentina, Colombia, and Venezuela; in the Old World, it is transmitted by various species of Phlebotomus; New World vectors are species of Lutzomyia; dogs and other carnivores are known as reservoir hosts in some areas. The intracellular amastigote form multiplies in macrophages and produces a reticuloendothelial hyperplasia grossly affecting the spleen and liver, with other lymphoid tissues being involved as well, resulting in severe hepatosplenomegaly, which usually is fatal if untreated.
L. donovani archibaldi L. donovani donovani.
L. donovani chagasi a subspecies of L. found in South America, chiefly in Brazil, producing visceral leishmaniasis; infections have been found in domestic dogs and in foxes, though the primary reservoir host is unclear. The vector remains undiscovered, and the taxonomic status of this subspecies is uncertain.
L. donovani donovani the type subspecies and agent of visceral leishmaniasis in Asia, Africa, and the Indian subcontinent; a few cases occur in the south central section of the former USSR, and in Iran, Iraq, and possibly Yemen; the dog and jackal are animal reservoirs. The form in Africa may be this subspecies, though the name L. donovani archibaldi is also used.
L. donovani infantum a strain or subspecies of L. donovani that causes visceral leishmaniasis in young children in Mediterranean countries; the reservoir is the domestic dog.
L. furunculosa former name for L. tropica.
L. major a species responsible for zoonotic cutaneous leishmaniasis in a large area of the Mediterranean region and Asia Minor. The animal reservoirs are usually ground squirrels, such as Rhombomys opimus in the former USSR and elsewhere in south central Asia, and other rodents in northwest India, the Middle East, and northern Africa; proven sandfly vectors include Phlebotomus papatasi, P. duboscqi, and P. salehi. SYN: L. tropica major.
L. mexicana the agent of many forms of cutaneous leishmaniasis, now considered a complex of several subspecies or possibly species, each with distinctive DNA and enzyme characteristics, distribution, and vector-reservoir host association, resulting in distinct manifestations of human leishmaniasis; reservoir hosts are extremely diverse and include a wide array of arboreal rodents as well as marsupials, primates, and small carnivores. Typical disease forms caused by this species are chiclero ulcer and diffuse cutaneous leishmaniasis, in contrast with mucocutaneous leishmaniasis, more characteristic of L. braziliensis infection. SYN: L. tropica mexicana.
L. mexicana amazonensis a particularly widespread form of L. mexicana in the Amazon basin (Bolivia, Brazil, Colombia, Ecuador, and southern Venezuela), where it infects a variety of forest rodents, the reservoirs of human infection. The disease is rare in humans, but the single or multiple lesions, when induced, rarely heal spontaneously; the disseminated form is common, but nasopharyngeal involvement does not occur. The vector is the sandfly Lutzomyia flaviscutellata.
L. mexicana garnhami a subspecies of L. mexicana, found in western Venezuela, causing single or multiple lesions in humans that heal spontaneously in about six months; the probable sandfly vector is Lutzomyia townsendi.
L. mexicana mexicana a species described from Mexico, Guatemala, and Belize; agent of a form of New World cutaneous leishmaniasis called chiclero ulcer, associated with chicle gum and mahogany forest workers. The New World sandfly, Lutzomyia olmeca, is a proven vector of this subspecies.
L. mexicana pifanoi a strain of L. mexicana accorded species status by those who consider it responsible for the diffuse or disseminated form of cutaneous leishmaniasis. It is responsible for this condition in Venezuela, where it was described, but it is now recognized that several species and subspecies of L. cause similar disseminated forms of leishmaniasis in widely separated regions (L. mexicana amazonensis, L. aethiopica); absence or suppression of the cell-mediated immune response in the host is also an important factor in induction of diffuse cutaneous leishmaniasis. SYN: L. pifanoi.
L. mexicana venezuelensis a recently described subspecies of L. mexicana from Venezuela that causes indolent, nodular, single lesions of cutaneous leishmaniasis to develop, sometimes with curable disseminated cutaneous leishmaniasis; infection has also been found in equines.
L. peruviana species of L. found infecting humans in the high Andean valleys of Peru and Bolivia; cause of a distinct form of New World cutaneous leishmaniasis called uta.
L. pifanoi SYN: L. mexicana pifanoi.
L. tropica species that is the causal agent of anthroponotic cutaneous leishmaniasis; formerly endemic throughout the Mediterranean basin, the Middle East, parts of the southern section of the area formerly known as the USSR and elsewhere in Asia, and also reported from western Africa; it is transmitted by Phlebotomus papatasi, P. sergenti, and related species of sandflies; small rodents such as various ground squirrels serve as reservoir hosts.
L. tropica major SYN: L. major.
L. tropica mexicana SYN: L. mexicana.

leishmania
leishmania, pl .leishmaniae (lesh-man′e-a)

A member of the genus L..

leishmaniae
leishmaniae

Plural of leishmania.

leishmaniasis
leishmaniasis (lesh′ma-ni′a-sis)

Infection with a species of Leishmania resulting in a clinically ill-defined group of diseases traditionally divided into four major types: 1) visceral l. (kala azar); 2) Old World cutaneous l.; 3) New World cutaneous l.; 4) mucocutaneous l.. Each is clinically and geographically distinct and each has in recent years been subdivided further into clinical and epidemiological categories. Transmission is by various sandfly species of the genus Phlebotomus or Lutzomyia. See tropical diseases, under disease. SYN: leishmaniosis.
acute cutaneous l. SYN: zoonotic cutaneous l..
American l., l. americana SYN: mucocutaneous l..
anergic l. SYN: diffuse cutaneous l..
anthroponotic cutaneous l. a form of Old World cutaneous l., usually with a prolonged incubation period and confined to urban areas. SYN: chronic cutaneous l., dry cutaneous l., urban cutaneous l..
canine l. a mild infection of dogs, usually confined to the muzzle or ears, produced by human disease-causing species of Leishmania; dogs therefore are important reservoirs of human infection, such as with visceral l. in the Mediterranean region.
chronic cutaneous l. SYN: anthroponotic cutaneous l..
cutaneous l. infection with promastigotes (leptomonads) of Leishmania tropica and of L. major inoculated into the skin by the bite of an infected sandfly, Phlebotomus (commonly P. papatasi); it is endemic in parts of Asia Minor, northern Africa, and India, and is known by innumerable names, including tropical sores, tropical ulcers, and other indications of locality ( e.g., Aleppo, Baghdad, Delhi, or Jericho boil; Aden ulcer; Biskra button); the ulcer begins as a papule that enlarges to a nodule and then breaks down into an ulcer. Leishmanial cells are seen within histiocytes in hematoxylin and eosin–stained tissue sections. Two distinctive clinical and epidemiological diseases are recognized: the more common and widespread zoonotic rural disease with a moist acute form, caused by L. major, with reservoir rodent hosts, and an urban, anthroponotic, dry, chronic form of l. caused by L. tropica, without a reservoir host, and now largely controlled. See zoonotic cutaneous l., anthroponotic cutaneous l.. SYN: Old World l..
diffuse l. SYN: diffuse cutaneous l..
diffuse cutaneous l. l. caused by several New and Old World species and strains of Leishmania (L. mexicana amazonensis, L. m. pifanoi, possibly L. m. garnhami and L. m. venezuelensis; in Ethiopia, L. aethiopica, and unidentified leishmanial agents in Namibia and Tanzania). The condition is associated with a suppressed cell-mediated immune response, so that the nonulcerating, nonnecrotizing cutaneous lesions can spread widely over the body; great numbers of parasite-filled macrophages are found in the dermal lesions. Healing does not appear to occur unless an acquired cellular hypersensitivity can develop. SYN: anergic l., diffuse l., disseminated cutaneous l., l. tegumentaria diffusa, pseudolepromatous l..
disseminated cutaneous l. SYN: diffuse cutaneous l..
dry cutaneous l. SYN: anthroponotic cutaneous l..
infantile l. visceral l. in infants, from Leishmania donovani infantum.
lupoid l. SYN: l. recidivans.
mucocutaneous l. a grave disease caused by Leishmania braziliensis braziliensis, endemic in southern Mexico and Central and South America, except for the equatorial region of Chile; the organism does not invade the viscera, and the disease is limited to the skin and mucous membranes, the lesions resembling the sores of cutaneous l. caused by L. mexicana or L. tropica; the chancrous sores heal after a time, but some months or years later, fungating and eroding forms of ulceration may appear on the tongue and buccal or nasal mucosa; many variants of the disease exist, marked by differences in distribution, vector, epidemiology, and pathology, which suggest that it may in fact be caused by a number of closely related etiologic agents. SEE ALSO: espundia. SYN: American l., l. americana, bubas, nasopharyngeal l., New World l..
nasopharyngeal l. SYN: mucocutaneous l..
New World l. SYN: mucocutaneous l..
Old World l. SYN: cutaneous l..
pseudolepromatous l. SYN: diffuse cutaneous l..
l. recidivans a partially healing leishmanial lesion caused by Leishmania tropica and characterized by an extreme form of cellular immune response, intense granuloma production, fibrinoid necrosis without caseation, and frequent development of satellite lesions that continue the production of granulomatous tissue without healing, sometimes over a period of many years; organisms are difficult to demonstrate but can be cultured. SYN: lupoid l..
rural cutaneous l. SYN: zoonotic cutaneous l..
l. tegumentaria diffusa SYN: diffuse cutaneous l..
urban cutaneous l. SYN: anthroponotic cutaneous l..
visceral l. 1. a chronic disease, occurring in India, China, Pakistan, the Mediterranean littoral, the Middle East, South and Central America, Asia, and Africa caused by Leishmania donovani and transmitted by the bite of an appropriate species of sandfly of the genus Phlebotomus or Lutzomyia; the organisms grow and multiply in macrophages, eventually causing them to burst and liberate amastigote parasites which then invade other macrophages; proliferation of macrophages in the bone marrow causes crowding out of erythroid and myeloid elements, resulting in leukopenia, and anemia, splenomegaly, and hepatomegaly which are characteristic, along with enlargement of lymph nodes; fever, fatigue, malaise, and secondary infections also occur; different strains of L. donovani occur; L. infantum in Eurasia, L. chagasi in Latin America. 2. visceral l. caused by Leishmania tropica, cultured from bone marrow aspirates of some military patients following the Gulf War. SYN: Assam fever, black sickness, Burdwan fever, cachectic fever, Dumdum fever, kala azar, tropical splenomegaly.
wet cutaneous l. SYN: zoonotic cutaneous l..
zoonotic cutaneous l. a form of cutaneous l. characterized by rural distribution of human cases near infected rodents, particularly communal ground squirrels; characterized by acute rapidly developing dermal lesions that become severely inflamed, with moist necrotizing sores or ulcers that heal in 2–8-months after a 2–4-month incubation period; among nonimmune immigrants, multiple lesions may develop, which heal more slowly and leave disabling or disfiguring scars. A strong delayed hypersensitivity and involvement of immune complexes play a role in necrosis, which is part of the healing process and of the strong specific immunity that follows. SYN: acute cutaneous l., rural cutaneous l., wet cutaneous l..

leishmaniosis
leishmaniosis (lesh′man-e-o′sis)

SYN: leishmaniasis.

leishmanoid
leishmanoid (lesh′ma-noyd)

Resembling leishmaniasis.
dermal l. SYN: post-kala azar dermal l..
post-kala azar dermal l. a chronic, progressive, granulomatous, nonulcerating hypopigmented nodular cutaneous eruption that may appear 6 months to 5 years after spontaneous or drug cure of visceral leishmaniasis (kala azar); this condition was first described in India and is most characteristic of kala azar in that country. SYN: dermal l..

Leiter
Leiter

Russell G., U.S. psychologist, *1901. See L. International Performance Scale.

Lejeune
Lejeune

Jerôme J.L.M., French cytogeneticist, 1926–1994. See L. syndrome.

Lembert
Lembert

Antoine, French surgeon, 1802–1851. See L. suture, Czerny-L. suture.

lemic
lemic (le′mik)

Relating to plague or any epidemic disease. [G. loimos, plague]

Leminorella
Leminorella (lem′in-o-rel′a)

A genus in the family Enterobacteriaceae containing two species, L. grimontii and L. richardii, that have been isolated from clinical material, primarily from fecal samples; its clinical importance is unclear at present.

Lemli
Lemli

Luc, 20th century U.S. pediatrician. See Smith-L.-Opitz syndrome.

lemmoblast
lemmoblast (lem′o-blast)

In an embryo, a cell of neural crest origin capable of forming a cell of the neurilemma sheath. [G. lemma, husk, + blastos, germ]

lemmocyte
lemmocyte (lem′o-sit)

One of the cells of the neurolemma. [G. lemma, husk, + kytos, cell]

lemniscus
lemniscus, pl .lemnisci (lem-nis′kus, -nis′i) [TA]

A bundle of nerve fibers ascending from sensory relay nuclei to the thalamus. SYN: fillet (1) . [L. from G. lemniskos, ribbon or fillet]
acoustic l. SYN: lateral l..
auditory l. SYN: lateral l..
gustatory l. the uncrossed secondary-sensory fiber system ascending from the rhombencephalic gustatory nucleus to the parabrachial nuclei (rostral pontine level) and directly to the thalamic gustatory nucleus (ventral postero-medial nucleus, pars parvicellularis).
lateral l. [TA] a bundle of ascending fibers that originate from the cochlear and auditory relay nuclei of the rhombencephalon, enter the trapezoid body, a transverse fiber stratum in which about half their number decussate, and from here turn rostrally along the lateral side of the spinothalamic tract; in the midbrain, it arches dorsally and enters the inferior colliculus in which all of its fibers terminate; the auditory pathway is transsynaptically extended from here by the brachium of the inferior colliculus to the medial geniculate body of the thalamus, from which in turn the auditory radiation leads to the auditory cortex; intercalated in the trapezoid body and along the ascending trajectory of the l. are several cell groups in which part of the fibers synapse. SYN: l. lateralis [TA] , acoustic l., auditory l., auditory tract, lateral fillet.
l. lateralis [TA] SYN: lateral l..
medial l. [TA] a band of white fibers originating from the gracile and cuneate nuclei and decussating in the lower medulla; thence it passes upward through the center of the medulla oblongata, close to the median raphe; on entering the pons it spreads out laterally to form a flat band ascending over the dorsal border of the pontine nuclei; in the mesencephalon it passes over the dorsal border of the substantia nigra and is displaced laterally by the red nucleus; passing medial to the medial geniculate body, the bundle enters and terminates in the ventral posterior nucleus of the thalamus. Throughout their course, the fibers retain a somatotopic order such that those originating from the gracile nucleus and representing the lower extremity lie lateral to those originating in the cuneate nucleus and representing the arm. The medial l. conveys somatic-sensory information involved in tactile discrimination (two-point discrimination), position sense, and vibration sense. SYN: l. medialis [TA] , medial fillet, Reil band (2) , Reil ribbon.
l. medialis [TA] SYN: medial l..
spinal l. [TA] SYN: spinothalamic tract.
l. spinalis [TA] SYN: spinothalamic tract.
trigeminal l. [TA] collective term denoting the fibers ascending from the sensory nuclei of the trigeminus; one such fiber system originates from the spinal trigeminal nucleus and from the principal sensory nucleus, decussates, and ascends as the anterior trigeminothalamic tract [TA] (ventral trigeminothalamic tract [TAalt]) in close association with the medial l. with which it enters the ventrobasal complex to terminate in the ventral posteromedial nucleus; a second, uncrossed, fiber group originating from the principal sensory nucleus that follows an ascending course through central parts of the mesencephalic tegmentum as the posterior trigeminothalamic tract [TA] (dorsal trigeminothalamic tract [TAalt]) also to terminate in the ventral posteromedial nucleus. The trigeminal l. conveys tactile, pain, and temperature impulses from the skin of the face, the mucous membranes of the nasal and oral cavities, and the eye, as well as proprioceptive information from the facial and masticatory muscles. SYN: l. trigeminalis [TA] .
l. trigeminalis [TA] SYN: trigeminal l..

lemon
lemon (lem′on)

The fruit of Citrus limon (family Rutaceae); a source of citric and ascorbic acid; the freshly expressed juice of the ripe fruit is used as a refrigerant diuretic in fever, in the form of lemonade. SYN: limon. [L. limon]

lemon yellow
lemon yellow

SYN: chrome yellow.

Lendrum
Lendrum

A.C., 20th century Scottish pathologist. See L. phloxine-tartrazine stain, Fraser-L. stain for fibrin.

Lenègre
Lenègre

Jean, 20th century French cardiologist. See L. disease, L. syndrome.

length
length (l)

Linear distance between two points.
arch l. the amount of space required for the permanent teeth as measured from the mesial aspect of the first molar on one side to the mesial aspect of the first molar on the opposite side, as measured through the contact points along an imaginary line of the dental arch.
available arch l. the amount of space available for the permanent teeth around the dental arch from first permanent molar to first permanent molar.
crown-heel l. (CH, CHL) l. of an outstretched embryo or fetus from skull vertex to heel. See Streeter developmental horizon(s).
crown-rump l. (CR, CRL) a measurement from the skull vertex to the midpoint between the apices of the buttocks of an embryo or fetus, that permits approximation of embryonic or fetal age.
greatest l. measurement from the cranial to caudal end of the embryo prior to folding.
required arch l. the sum of the mesiodistal widths of the permanent teeth from first permanent molar to first permanent molar.
resting l. the l. at rest from which a muscle develops maximum isometric tension.
spinal l. (SL) a measurement from the distal surface of the embryo where the plane passes through the developing eye (this is the cranial limit of the spinal cord) down to the rump.

Lenhossék
Lenhossék

Michael (Mihály) von, Hungarian anatomist, 1863–1937. See L. processes, under process.

lenitive
lenitive (len′i-tiv)

1. Soothing; relieving discomfort or pain. 2. Rarely used term for a demulcent. [L. lenio, pp. lenitus, to soften, fr. lenis, mild]

Lennert
Lennert

Karl, *1921. See L. lymphoma, L. classification.

Lennox
Lennox

William G., U.S. neurologist, 1884–1960. See L. syndrome, L.-Gastaut syndrome.

Lenoir
Lenoir

Camille A.H., French anatomist, *1867. See L. facet.

lens
lens (lenz) [TA]

1. A transparent material with one or both surfaces having a concave or convex curve; acts upon electromagnetic energy to cause convergence or divergence of light rays. 2. [TA] The transparent biconvex cellular refractive structure lying between the iris and the vitreous humor, consisting of a soft outer part (cortex) with a denser part (nucleus), and surrounded by a basement membrane (capsule); the anterior surface has a cuboidal epithelium, and at the equator the cells elongate to become l. fibers. SYN: crystalline l.. [L. a lentil]
achromatic l. a compound l. made of two or more lenses having different indices of refraction, so correlated as to minimize chromatic aberration.
acoustic l. in ultrasonography, a l. used to focus or diverge a sound beam; may be simulated by electronic manipulation of signals.
aplanatic l. a l. designed to correct spherical aberration and coma (q.v.). SYN: periscopic meniscus.
apochromatic l. a compound l. designed to correct both spherical and chromatic aberrations.
aspheric l. a l. with a paraboloidal surface that eliminates spherical aberration.
astigmatic l. SYN: cylindrical l..
bandage contact l. a contact l. placed on the cornea to cover a defect.
biconcave l. a l. that is concave on two opposing surfaces. SYN: concavoconcave l., double concave l..
biconvex l. a l. with both surfaces convex. SYN: convexoconvex l., double convex l..
bifocal l. a l. used in cases of presbyopia, in which one portion is suited for distant vision, the other for reading and close work in general; the reading addition may be cemented to the l., fused to the front surface, or ground in one-piece form; other bifocal lenses are the flat-top Franklin type, or blended invisible.
cataract l. any l. prescribed for aphakia.
l. clock SYN: Geneva l. measure.
compound l. an optical system of two or more lenses.
concave l. a diverging minus power l.. SYN: minus l..
concavoconcave l. SYN: biconcave l..
concavoconvex l. a converging meniscus l. that is concave on one surface and convex on the opposite surface.
contact l. a l. that fits over the cornea and sclera or cornea only; used to correct refractive errors.
convex l. a converging l.. SYN: plus l..
convexoconcave l. a minus power l. having one surface convex and the opposite surface concave, with the latter having the greater curvature.
convexoconvex l. SYN: biconvex l..
corneal l. contact l. of plastic without scleral portions.
crystalline l. SYN: l. (2) .
cylindrical l. (cyl., C) a l. in which one of the surfaces is curved in one meridian and less curved in the opposite meridian; e.g., a teaspoon or a football. SYN: astigmatic l..
decentered l. a l. so mounted that the visual axis does not pass through the axis of the l..
dislocation of l. SYN: ectopia lentis.
double concave l. SYN: biconcave l..
double convex l. SYN: biconvex l..
eye l. the upper of the two planoconvex lenses of Huygens ocular. SYN: ocular l..
field l. the lower of the two planoconvex lenses of Huygens ocular.
foldable intraocular l. a l. often made of silicone or an acrylic polymer that may be doubled over for implantation into the eye following cataract removal.
Fresnel l. a l. with a surface consisting of a concentric series of zones that duplicate the power of a l. or prism but with less thickness. SYN: lighthouse l..
Hruby l. a non–contact l. mounted on a slitlamp used for evaluating the retina.
immersion l. an objective (for a microscope) constructed in such a manner that the lower l. may be moved downward into direct contact with a fluid which is placed on the object being examined; by using a fluid with a refractive index closely similar to that of glass, the loss of light is minimized.
lighthouse l. SYN: Fresnel l..
meniscus l. a l. having a spherical concave curve on one side and a spherical convex curve on the other. SYN: articular crescent, articular meniscus, intraarticular cartilage (2) , meniscus articularis, meniscus (1) .
minus l. SYN: concave l..
multifocal l. a l. with segments providing two or more powers; commonly, a trifocal l..
ocular l. SYN: eye l..
omnifocal l. a l. for near and distant vision in which the reading portion is a continuously variable curve.
orthoscopic l. a spectacle l. corrected for distortion and curvature of the periphery.
periscopic l. a l. with 1.25 D base curve.
photochromic l. a light-sensitive spectacle l. that reduces light transmission in sunlight and increases transmission in reduced light.
planoconcave l. a l. that is flat on one side and concave on the other.
planoconvex l. a l. that is flat on one side and convex on the other.
plus l. SYN: convex l..
safety l. a l. that meets government specifications of impact resistance; the increased impact resistance required for safety lenses is obtained by tempering, by an ion-exchange process, or by using laminated or plastic lenses.
slab-off l. a spectacle l. with a base-up prism below; used in unequal myopia to equalize image displacement when reading.
spherical l. (S, sph.) a l. in which all refracting surfaces are spherical.
spherocylindrical l. a combined spherical and cylindrical l., one surface being spherical, the other cylindrical. SYN: spherocylinder.
toric l. a l. in which both meridians are curved but not to the same degree.
trial lenses a series of cylindrical and spherical lenses used in testing vision.
trifocal l. a l. with segments of three focal powers: distant, intermediate, and near.

lens clock
lens clock

See under lens.

lensectomy
lensectomy (len-sek′to-me)

Removal of the lens of the eye by an infusion-aspiration cutter; often done by puncture incision through the pars plana in the course of vitrectomy. [lens + G. ektome, excision]

lensometer
lensometer (len-zom′e-ter)

An instrument to measure the power and cylindrical axis of a spectacle lens. SYN: focimeter, vertometer. [lens + G. metron, measure]

lensopathy
lensopathy (lenz-op′a-the)

The process by which tear proteins are deposited on a contact lens. [lens + G. pathos, suffering]

lenticonus
lenticonus (len-ti-ko′nus)

Conical projection of the anterior or posterior surface of the lens of the eye, occurring as a developmental anomaly. [lens + L. conus, cone]

lenticula
lenticula (len-tik′u-la)

SYN: lentiform nucleus. [L. dim. of lens]

lenticular
lenticular (len-tik′u′lar)

1. Relating to or resembling a lens of any kind. 2. Of the shape of a lentil. [L. lenticula, a lentil]

lenticulo-optic
lenticulo-optic (len-tik′u-lo-op′tik)

Relating to the lentiform nucleus and the optic tract; specifically refers to branches of the middle cerebral artery considered to supply these structures.

lenticulopapular
lenticulopapular (len-tik′u-lo-pap′u-lar)

Indicating an eruption with dome-shaped or lens-shaped papules.

lenticulostriate
lenticulostriate (len-tik′u-lo-stri′at)

Relating to the lenticular nucleus and the caudate nucleus; specifically refers to branches of the middle cerebral artery supplying these gray masses.

lenticulothalamic
lenticulothalamic (len-tik′u-lo-tha-lam′ik)

Pertaining to the lentiform (lenticular) nucleus and the thalamus.

lenticulus
lenticulus, pl .lenticuli (len-tik′u-lus, -li)

Seldom-used term for an intraocular lens prosthesis placed in the anterior or posterior chamber of the eye, or attached to the iris after cataract extraction. SYN: prosthetophacos, pseudophacos. [L. dim. of lens, lentis, a little lens]

lentiform
lentiform (len′ti-form)

Lens-shaped.

lentigines
lentigines (len-tij′i-nez)

Plural of lentigo. [L.]

lentiginosis
lentiginosis (len-tij-i-no′sis)

Presence of lentigines in very large numbers or in a distinctive configuration.
centrofacial l. [MIM*151000 & MIM*151001] uncommon autosomal dominant syndrome of small hyperpigmented macules in a horizontal band across the center of the face at one year, increasing in number up to ten years, and associated with skeletal and neural defects.
generalized l. lentigines occurring singly or in groups from infancy onward.

lentiglobus
lentiglobus (len-ti-glo′bus)

Rare congenital anomaly with a spheroid elevation on the posterior surface of the lens of the eye. [lens + L. globus, sphere]

lentigo
lentigo, pl .lentigines (len-ti′go, len-tij′i-nez)

A benign, acquired brown macule resembling a freckle except that the border is usually regular and microscopic elongation of rete ridges is present, with increased melanocytes and melanin pigment in the basal cell layer. SEE ALSO: junction nevus. SYN: l. simplex. [L. fr. lens (lent-), a lentil]
l. maligna a brown or black mottled, irregularly outlined, slowly enlarging lesion resembling a l. in which there are increased numbers of scattered atypical melanocytes in the epidermis, usually occurring on the face of older persons; after many years the dermis may be invaded and the lesion is then termed l. maligna melanoma. SYN: Hutchinson freckle, melanotic freckle.
senile l. a variably pigmented benign l. occurring on exposed skin of older white persons. SYN: liver spot, solar l..
l. simplex SYN: l..
solar l. SYN: senile l..

Lentivirinae
Lentivirinae (len′ti-vir′i-ne)

Term formerly used to describe a subfamily of nononcogenic viruses (family Retroviridae) that includes the slow viruses of sheep (visna virus and maedi virus) and human T-cell lymphotropic viruses, including human immunodeficiency viruses 1 and 2. The viruses resemble the C-type RNA tumor viruses (Oncovirinae) in many ways, including production of reverse transcriptase. [L. lentus, sluggish, slow]

lentivirus
lentivirus (len′ti-vi-rus)

A genus in the family Retroviridae containing 5 serogroups that reflect the host with which they are associated. Among the primate lentiviruses are human immunodeficiency viruses 1 and 2.

lentogenic
lentogenic (len-to-jen′ik)

Denoting the virulence of a virus capable of inducing lethal infection in embryonic hosts after a long incubation period and an inapparent infection in immature and adult hosts; the term is used in characterizing Newcastle disease virus, particularly strains used as vaccines administered in water or as sprays, i.e., mild or avirulent strains. [L. lentus, sluggish, inactive, + G. -gen, producing]

lentula
lentula, lentulo (len′tu-la, -lo)

A motorized, flexible, spiral wire instrument used in dentistry to apply paste filling material into the root canal(s) of a tooth. [L. lentus, pliant, flexible]

leontiasis
leontiasis (le-on-ti′a-sis)

The ridges and furrows on the forehead and cheeks of patients with advanced lepromatous leprosy, giving a leonine appearance. SYN: leonine facies. [G. leon (leont-), lion]
l. ossea SYN: megacephaly.

LEOPARD
LEOPARD [MIM*151100]

Acronym for lentigines (multiple), electrocardiographic abnormalities, ocular hypertelorism, pulmonary stenosis, abnormalities of genitalia, retardation of growth, and deafness (sensorineural); of autosomal dominant inheritance.

leopard's bane
leopard's bane

SYN: arnica.

Leopold
Leopold

Christian Gerhard, German physician, 1846–1911. See L. maneuvers, under maneuver.

Lepehne
Lepehne

Georg, German physician, *1887. See L.-Pickworth stain.

leper
leper (lep′er)

A person who has leprosy. [G. lepra]

lepidic
lepidic (le-pid′ik)

Relating to scales or a scaly covering layer. [G. lepis (lepid-), scale, rind]

Lepidoptera
Lepidoptera (lep-i-dop′ter-a)

An order of insects composed of the moths and butterflies, characterized by wings covered with delicate scales. [G. lepis, scale, + pteron, wing]

Leporipoxvirus
Leporipoxvirus (lep′o-ri-poks′vi-rus)

The genus of viruses (family Poxviridae) that comprises the fibroma and myxoma viruses of rabbits; unlike the orthopoxviruses, they are ether-sensitive. [L. leporis, gen. of lepus, a hare, + virus]

lepothrix
lepothrix (lep′o-thriks)

SYN: trichomycosis axillaris. [G. lepos, rind, husk, + thrix, hair]

leprechaunism
leprechaunism (lep′re-kawn-izm) [MIM*246200]

A congenital form of dwarfism characterized by extreme growth retardation, endocrine disorders, and emaciation, with elfin facies and large, low-set ears; autosomal recessive inheritance; caused by mutation in the insulin receptor gene (INSR) on 19p. SYN: Donohue disease, Donohue syndrome. [Irish leprechaun, elf]

leprid
leprid

Early cutaneous lesion of leprosy. [G. lepra, leprosy, + -id (1)]

leproma
leproma (le-pro′ma)

A fairly well-circumscribed discrete focus of granulomatous inflammation, caused by Mycobacterium leprae, which consists chiefly of an accumulation of large mononuclear phagocytic cells in which the cytoplasm seems finely vacuolated ( i.e., foam cells); the foamlike character of the macrophages is related to the engulfing of numerous acid-fast organisms. [G. lepros, scaly, + -oma, tumor]

lepromatous
lepromatous (lep-ro′ma-tus)

Pertaining to, or characterized by, the features of a leproma.

lepromin
lepromin (lep′ro-min)

An extract of tissue infected with Mycobacterium leprae used in skin tests to classify the stage of leprosy. SEE ALSO: l. reaction, test.

leprosarium
leprosarium (lep′ro-sar′e-um)

A hospital especially designed for the care of those suffering from leprosy, especially those who need expert care.

leprosery
leprosery (lep′ro-ser-e)

A leper home or colony.

leprostatic
leprostatic (lep-ro-stat′ik)

1. Inhibiting to the growth of Mycobacterium leprae. 2. An agent having this action.

leprosy
leprosy (lep′ro-se)

1. A chronic granulomatous infection caused by Mycobacterium leprae affecting the cooler body parts, especially the skin, peripheral nerves, and testes. L. is classified into two main types, lepromatous and tuberculoid, representing extremes of immunologic response. 2. A name used in the Bible to describe various cutaneous diseases, especially those of a chronic or contagious nature, which probably included psoriasis and leukoderma. SYN: Hansen disease. [G. lepra, from lepros, scaly]
anesthetic l. a form of l. chiefly affecting the nerves, marked by hyperesthesia succeeded by anesthesia, and by paralysis, ulceration, and various trophic disturbances, terminating in gangrene and mutilation. SYN: Danielssen disease, Danielssen-Boeck disease, dry l., trophoneurotic l..
borderline l. a form of l. that is very unstable immunologically; the cutaneous nerves frequently contain bacilli, but the lepromin test is usually negative; cutaneous lesions are composed of flat bands or plaques. SYN: dimorphous l..
dimorphous l. SYN: borderline l..
dry l. SYN: anesthetic l..
histoid l. a form of lepromatous l. with lesions microscopically resembling dermatofibroma or other spindle-celled tumors.
indeterminate l. a transitory form of l. in which the immunologic status is not yet formed, and the histologic and clinical features are not yet characteristic of any of the major types of l..
lepromatous l. a form of l. in which nodular cutaneous lesions are infiltrated, have ill-defined borders, and are bacteriologically positive; the lepromin test is negative, i.e., the immunologic mechanism of the patient is not responsive to the Mycobacterium leprae infection.
Lucio l. an acute form occurring in pure diffuse lepromatous l. presenting irregularly shaped, intensely erythematous, tender plaques, especially of the legs, with tendency to ulceration and scarring. SYN: Lucio l. phenomenon.
macular l. a form of tuberculoid l. in which the lesions are small, hairless, and dry, and are erythematous in light skin and hypopigmented or copper-colored in dark skin.
mutilating l. a late stage of anesthetic l..
nodular l. SYN: tuberculoid l..
smooth l. SYN: tuberculoid l..
trophoneurotic l. SYN: anesthetic l..
tuberculoid l. a benign, stable, and resistant form of the disease in which the lepromin reaction is strongly positive and in which the lesions are erythematous, insensitive, infiltrated plaques with clear-cut edges. SYN: nodular l., smooth l..

leprotic
leprotic (lep-rot′ik)

SYN: leprous.

leprous
leprous (lep′rus)

Relating to or suffering from leprosy. SYN: leprotic.

-lepsis -lepsis, -lepsy

A seizure. [G. lepsis]

leptandra
leptandra (lep-tan′dra)

Dried rhizome and roots of Veronicastrum virginicum (family Serophulariaceae). Indigenous to North America. Formerly used as a cathartic. SYN: black root, Culver root.

leptin leptin (lep′tin)

A helical protein secreted by adipose tissue and acting on a receptor site in the ventromedial nucleus of the hypothalamus to curb appetite and increase energy expenditure as body fat stores increase. L. levels are 40% higher in women, and show a further 50% rise just before menarche, later returning to baseline levels; levels are lowered by fasting and increased by inflammation. [G. leptos, thin, + -in] Human genes encoding both l. (locus 7q31.3) and the l. receptor site (1p31) have been identified. Laboratory mice having mutations on the ob gene, which encodes l., become morbidly obese, diabetic, and infertile; administration of l. to these mice improves glucose tolerance, increases physical activity, reduces body weight by 30%, and restores fertility. Mice with mutations of the db gene, which encodes the l. receptor, also become obese and diabetic but do not improve with administration of l.. Although mutations in both the l. and l. receptor genes have been found in a small number of morbidly obese human subjects with abnormal eating behavior, the majority of obese persons do not show such mutations, and have normal or elevated circulating levels of l.. L. enhances insulin-mediated glucose transport into adipose cells in vitro. In preliminary trials, both lean and overweight persons have shown modest weight loss with daily subcutaneous injections of recombinant methionyl human l. over several months. All subjects followed weight-reduction diets during the trial period. Weight loss in some subjects receiving l. did not exceed that achieved by subjects receiving placebo, but when significant weight reduction occurred, it was proportionate to dosage. The immune deficiency seen in starvation may result from diminished l. secretion. Mice lacking the gene for l. or its receptor show impairment of T-cell function, and in laboratory studies l. has induced a proliferative response in human CD4 lymphocytes.

lepto- lepto-

Light, thin, frail. [G. leptos, slender, delicate, weak]

leptocephalous
leptocephalous (lep-to-sef′a-lus)

Having an abnormally tall, narrow cranium. [lepto- + G. kephale, head]

leptocephaly
leptocephaly (lep-to-sef′a-le)

A malformation characterized by an abnormally tall, narrow cranium. [lepto- + G. kephale, head]

leptochromatic
leptochromatic (lep′to-kro-mat′ik)

Having a very fine chromatin network.

leptocyte
leptocyte (lep′to-sit)

A target or Mexican hat cell, i.e., an unusually thin or flattened red blood cell in which there is a central rounded area of pigmented material, a middle clear zone that contains no pigment, and an outer pigmented rim at the edge of the cell. Leptocytes are thought to be erythrocytes in which the cellular envelope or membrane is unusually large in proportion to its contents. [lepto- + G. kytos, cell]

leptocytosis
leptocytosis (lep′to-si-to′sis)

The presence of leptocytes in the circulating blood, as in thalassemia, some instances of jaundice (even in the absence of anemia), occasional examples of hepatic disease (in the absence of jaundice), and some patients who have had the spleen removed.

leptodactylous
leptodactylous (lep-to-dak′ti-lus)

Having slender fingers. [lepto- + G. daktylos, finger]

leptomeningeal
leptomeningeal (lep′to-me-nin′je-al)

Pertaining to the leptomeninges.

leptomeninges
leptomeninges, leptomeninx, gen. leptomeninx (lep-to-me-nin′jez, lep′to-me′ninks, lep′to-me′ninks) [TA]

SYN: leptomeninx. [lepto- + G. meninx, pl. meninges, membrane]

leptomeningitis
leptomeningitis (lep′to-men-in-ji′tis)

Inflammation of leptomeninges. SEE ALSO: arachnoiditis. SYN: pia-arachnitis.
basilar l. inflammation of the arachnoid at the base of the brain; often found in chronic meningitis of tuberculous, luetic, or mycotic origin.

leptomere
leptomere (lep′to-mer)

A very minute particle of living matter; Asclepiades believed the body was composed of an aggregation of vast numbers of leptomeres. [lepto- + G. meros, part]

leptomonad
leptomonad (lep′to-mo′nad, lep-tom′o-nad)

1. Common name for a member of the genus Leptomonas. 2. See promastigote.

Leptomonas
Leptomonas (lep′to-mo′nas, lep-tom′o-nus)

A genus of asexual, monogenetic, parasitic flagellates (family Trypanosomatidae) commonly found in the hindgut of insects. [lepto- + G. monas, unit]

leptonema
leptonema (lep-to-ne′ma)

SYN: leptotene. [lepto- + G. nema, thread]

leptophonia
leptophonia (lep′to-fo′ne-a)

SYN: hypophonia. [lepto- + G. phone, sound, voice]

leptophonic
leptophonic (lep′to-fon′ik)

Weak-voiced.

leptopodia
leptopodia (lep-to-po′de-a)

The condition of having slender feet. [lepto- + G. pous, foot]

leptoprosopia
leptoprosopia (lep′to-pro-so′pe-a)

Narrowness of the face. [lepto- + G. prosopon, face]

leptoprosopic
leptoprosopic (lep′to-pro-so′pik)

Having a thin, narrow face. Cf.:leptosomatic.

leptorrhine
leptorrhine (lep′to-rin)

Having a thin nose. Applied to a skull with a nasal index below 47 (Frankfort agreement) or 48 (Broca). [lepto- + G. rhis, nose]

leptoscope
leptoscope (lep′to-skop)

An apparatus for measuring cell membranes.

leptosomatic
leptosomatic, leptosomic (lep′to-so-mat′ik, -to-so′mik)

Having a slender, light, or thin body. [lepto- + G. soma, body]

Leptospira
Leptospira (lep′to-spi′ra)

A genus of motile aerobic bacteria (order Spirochaetales) containing thin, tightly coiled organisms 6–20 μm in length. They possess an axial filament, and one or both ends may be bent into a semicircular hook. They stain with difficulty except with Giemsa stain or silver impregnation. Associated with icterohemorrhagic fever. They include 7 pathogens and 3 nonpathogenic species; the type species is L. interrogans. [lepto- + G. speira, a coil]
L. interrogans a species containing multiple named pathogenic serovars. Causative agent of leptospirosis. It is the type species of the genus L..

leptospire
leptospire (lep′to-spir)

Common name for any organism belonging to the genus Leptospira.

leptospirosis
leptospirosis (lep′to-spi-ro′sis)

Infection with Leptospira interrogans.
anicteric l. infection with one of the species of the Leptospira group, usually mild, with limited liver and kidney involvement, as opposed to Weil disease.
l. icterohemorrhagica (ik′ter-o-hem-or-aj′i-ka) SYN: icterohemorrhagic fever.

leptospiruria
leptospiruria (lep′to-spi-roo′re-a)

Presence of species of the genus Leptospira in the urine, as a result of leptospirosis in the renal tubules.

leptotene
leptotene (lep′to-ten)

Early stage of prophase in meiosis in which the chromosomes contract and become visible as long filaments well separated from each other. SYN: leptonema. [lepto- + G. tainia, band, tape]

leptothricosis
leptothricosis (lep′to-thri-ko′sis)

Obsolete term for any disease caused by the now invalid genus Leptothrix.

Leptothrix
Leptothrix (lep′to-thriks)

A now invalid genus of sheathed organisms closely related to the genus Sphaerotilus found in fresh water.

Leptotrichia
Leptotrichia (lep-to-trik′e-a)

A genus of anaerobic, nonmotile bacteria containing Gram-negative, straight or slightly curved rods, 5–15 μm in length, with one or both ends rounded, often pointed. Granules are distributed evenly along the long axis, and one or more large granules may localize near the end of the cell. Branched or clubbed forms do not occur. Two or more cells join together and form septate filaments of varying length; in older cultures, filaments up to 200 μm may form and twist around each other; large, coccoid bodies may be found within a filament as a cell lyses. Carbon dioxide is essential for optimal growth. Lactic acid is produced from glucose. These organisms occur in the oral cavity of humans. The type species is L. buccalis. [lepto- + G. thrix, hair]
L. buccalis a bacterial species found in the human mouth rarely found in the blood of immunocompromised patients; it is the type species of the genus L..

Leptotrombidium
Leptotrombidium (lep′to-trom-bid′e-um)

An important genus of trombiculid mites, formerly considered a subgenus of the genus Trombicula, which includes all of the vectors of scrub typhus (tsutsugamushi disease). Members of L. that serve as vectors of scrub typhus are within the L. deliense group: L. akamushi is the classical vector in Japan; L. deliense is the primary vector, extending from New Guinea, Australia, the Philippines, China, and Southeast Asia to western Pakistan; L. fletcheri is found in Malaysia, New Guinea, and the Philippines. Some eight other species have also been implicated in scrub typhus transmission in more limited areas.
L. akamushi one of two species, the other being L. deliensis (T. deliensis), implicated in the transmission of Rickettsia tsutsugamushi, agent of tsutsugamushi disease in Japan and elsewhere in the Orient; the larvae of these species are characteristic parasites of rodents, which therefore are reservoirs of human infections, although the mites themselves are also reservoirs, as their rickettsial parasites are transovarially transmitted from generation to generation (a requirement for transmission to humans as only larval mites feed parasitically and then only once in their lifetimes). SYN: Trombicula akamushi.

lergotrile
lergotrile (ler′go-tril)

A derivative of ergot which exerts agonistic properties on dopamine receptors; similar to bromocriptine and lisuride.

Leri
Leri

André, French orthopedic surgeon, 1875–1930. See L. pleonosteosis, L. sign, L.-Weill disease, L.-Weill syndrome.

Leriche
Leriche

René, French surgeon, 1879–1955. See L. operation, L. syndrome.

Lermoyez
Lermoyez

Marcel, French otolaryngologist, 1858–1929. See L. syndrome.

Lerner
Lerner

I.M., U.S. population geneticist, 1910–1967. See L. homeostasis.

Leroy
Leroy

Edgar August, French physician, *1883. See Fiessinger-L.-Reiter syndrome.

LES
LES

Acronym for lower esophageal sphincter; Lambert-Eaton syndrome.

lesbian
lesbian (lez′be-an)

1. A female homosexual. 2. Pertaining to homosexuality between women. See gay.

lesbianism
lesbianism (lez′be-an-izm)

Homosexuality between women. SYN: sapphism. [G. lesbios, relating to the island of Lesbos]

Lesch
Lesch

Michael, U.S. pediatrician, *1939. See L.-Nyhan syndrome.

Leser
Leser

Edmund, German surgeon, 1828–1916. See L.-Trélat sign.

lesion
lesion (le′zhun)

1. A wound or injury. 2. A pathologic change in the tissues. 3. One of the individual points or patches of a multifocal disease. [L. laedo, pp. laesus, to injure]
Baehr-Lohlein l. SYN: Lohlein-Baehr l..
Bankart l. a tear of the anterior glenoid labrum accompanying detachment of the inferior glenohumeral ligament.
benign lymphoepithelial l. benign tumor-like masses of lymphoid tissue in the parotid gland, containing scattered small, mainly solid islands of epithelial cells. SYN: Godwin tumor.
Bracht-Wächter l. a focal collection of lymphocytes and mononuclear cells within the myocardium in bacterial endocarditis.
caviar l. a dilated vein or varicule existing in the venous collecting system under the tongue.
coin l. of lungs SYN: nodular opacity.
Dieulafoy l. an abnormally large submucosal artery located in the proximal stomach that may be the site of acute and recurrent episodes of massive hemorrhage.
Duret l. small hemorrhage(s) in the floor of the fourth ventricle or beneath the aqueduct of Sylvius.
Ghon primary l. SYN: Ghon tubercle.
gross l. a l. plainly visible to the naked eye.
high-grade squamous intraepithelial l. (HSIL, HGSIL) term used in the Bethesda system for reporting cervical/vaginal cytologic diagnosis to describe a spectrum of noninvasive cervical epithelial abnormalities, including moderate and severe dysplasia, carcinoma in situ, and cervical intraepithelial neoplasia grades 2 and 3. SEE ALSO: Bethesda system, ASCUS, atypical glandular cells of undetermined significance, under cell, low-grade squamous intraepithelial l..
Hill-Sachs l. an irregularity seen in the head of the humerus following anterior dislocation of the shoulder; caused by impaction of posterolateral portion of the head of the humerus against the anterior edge of the glenoid.
Janeway l. one of the stigmata of infectious endocarditis: irregular, erythematous, flat, painless macules on the palms, soles, thenar and hypothenar eminences of the hands, tips of the fingers, and plantar surfaces of the toes; rarely a diffuse rash. In acute endocarditis the lesions may be hemorrhagic or purple.
Lohlein-Baehr l. focal embolic glomerulonephritis occurring in bacterial endocarditis. SYN: Baehr-Lohlein l..
lower motor neuron l. injury to motor cells in the brainstem or spinal cord, or of the axons derived from them.
low-grade squamous intraepithelial l. (LGSIL, LSIL) term used in the Bethesda system for reporting cervical/vaginal cytologic diagnosis to describe a spectrum of noninvasive cervical epithelial abnormalities; these lesions include the cellular changes associated with human papilloma virus cytopathologic effect and mild dysplasia (cervical intraepithelial neoplasia grade 1). SEE ALSO: Bethesda system, reactive changes, under change, ASCUS, atypical glandular cells of undetermined significance, under cell.
Mallory-Weiss l. SYN: Mallory-Weiss syndrome.
precancerous l. a noninvasive l. with a predictable likelihood of becoming malignant; e.g., actinic keratosis.
radial sclerosing l. a variant of sclerosing adenosis of the breast with central scar formation and radiating hyperplastic ducts. SYN: radial scar.
ring-wall l. a small ring hemorrhage in the brain that stimulates proliferation of a glial ring.
supranuclear l. injury to cerebral descending (corticonuclear) fibers above the brainstem or spinal motor nerve nucleus. SYN: upper motor neuron l..
upper motor neuron l. SYN: supranuclear l..
wire-loop l. thickening of the basement membrane, with fibrinoid staining, of scattered peripheral capillaries in renal glomeruli; characteristic of renal involvement in systemic lupus erythematosus; the appearance of an affected capillary wall resembles a loop used in microbiology.

Lesser
Lesser

Ladislaus Leo, German surgeon born in Poland, 1846–1925. See L. triangle.

Lesshaft
Lesshaft

Pjotr F., Russian physician, 1836–1909. See L. triangle.

LET
LET

Abbreviation for linear energy transfer.

lethal
lethal (le′thal)

Pertaining to or causing death; denoting especially the causal agent. [L. letalis, fr. letum, death]
clinical l. a disorder that culminates in premature death.
genetic l. a disorder that prevents effective reproduction by those affected; e.g., Klinefelter syndrome.

lethality
lethality (le-thal′i-te)

The quality or state of being lethal.

lethargy
lethargy (leth′ar-je)

Relatively mild impairment of consciousness resulting in reduced alertness and awareness; this condition has many causes but is ultimately due to generalized brain dysfunction. [G. lethargia, drowsiness]

LETS
LETS

Acronym for large, external transformation-sensitive fibronectin. See fibronectins.

Letterer
Letterer

Erich, German pathologist, *1895. See L.-Siwe disease.

Leu
Leu

Symbol for leucine; leucyl.

leuc- leuc-, leuco-

White; white blood cell. See leuko-, leuk-. [G. leukos, white]

leucin
leucin (loo′sin)

SYN: leukin.

leucine
leucine (L, Leu) (loo′sen)

2-Amino-4-methylvaleric acid;the l-isomer is one of the amino acids found in proteins; a nutritionally essential amino acid.
l. aminopeptidase aminopeptidase (cytosol).
l. dehydrogenase an enzyme that catalyzes the reaction of l-l., water, and NAD⁺ to produce NADH, ammonia, and 4-methyl-2-oxopentanoate; used in the treatment of certain tumors.
l. zipper a structural motif found in a number of proteins ( e.g., some of the DNA-binding regulatory proteins) in which leucyl residues align along one edge of the helix and can interdigitate with a similar structure on another protein molecule. [Zipper, orig. a trademark for a fastening device with two rows of interlocking teeth]

leucinosis
leucinosis (loo′si-no′sis)

A condition in which there is an abnormally large proportion of leucine in the tissues and body fluids.

leucinuria
leucinuria (loo-si-noo′re-a)

The excretion of leucine in the urine.

leucoharmine
leucoharmine (loo-ko-har′men)

SYN: harmine.

leucoline
leucoline (loo′ko-len)

SYN: quinoline (1) .

leucomethylene blue
leucomethylene blue (lu′ko-meth′i-len)

The reduced and colorless form of methylene blue. SYN: methylene white.

Leuconostoc
Leuconostoc (loo-ko-nos′tok)

A genus of microaerophilic to facultatively anaerobic bacteria (family Lactobacillaceae) containing Gram-positive, spherical cells which may, under certain conditions, lengthen and become pointed and even form rods. Lactic and acetic acids are produced by these organisms. They are found in plant juices and in milk. The type species is L. mesenteroides. [G. leukos, white, + nostoc, a genus of algae (a word coined by Paracelsus)]
L. mesenteroides a species found in fermenting vegetables and other plant materials and in prepared meat products; it is an active slime (dextran) producer, the dextran commonly used as a plasma expander; it is the type species of the genus L..

leuco patent blue
leuco patent blue (loo′ko pat′ent) [C.I. 42051]

A sulfonated triphenylmethane dye reduced and decolorized with zinc and acetic acid to produce a stable solution; used to demonstrate hemoglobin peroxidase. SYN: patent blue V.

leucovorin
leucovorin (loo′ko-vor-in)

SYN: folinic acid.
l. calcium the calcium salt of l. (folinic acid); used to counteract toxic effects of folic acid antagonists, for the treatment of megaloblastic anemias, and as an adjunct to cyanocobalamin in pernicious anemia. SYN: calcium folinate.

Leudet
Leudet

Théodor E., French physician, 1825–1887. See L. tinnitus.

leuenkephalin
leuenkephalin (loo-en-kef′a-lin)

See enkephalins.

leuk- leuk-

See leuko-.

leukanemia
leukanemia (loo-ka-ne′me-a)

Obsolete term for erythroleukemia. [leukemia + anemia]

leukapheresis
leukapheresis (look′a-fe-re′sis)

A procedure, analogous to plasmapheresis, in which leukocytes are removed from the withdrawn blood and the remainder of the blood is retransfused into the donor. [leuko- + G. aphairesis, a withdrawal]

leukemia
leukemia (loo-ke′me-a)

Progressive proliferation of abnormal leukocytes found in hemopoietic tissues, other organs, and usually in the blood in increased numbers. L. is classified by the dominant cell type, and by duration from onset to death. This occurs in acute l. within a few months in most cases, and is associated with acute symptoms including severe anemia, hemorrhages, and slight enlargement of lymph nodes or the spleen. The duration of chronic l. exceeds one year, with a gradual onset of symptoms of anemia or marked enlargement of spleen, liver, or lymph nodes. SYN: leukocytic sarcoma. [leuko- + G. haima, blood]
acute lymphocytic l. (ALL) lymphocytic l..
acute promyelocytic l. l. presenting as a severe bleeding disorder, with infiltration of the bone marrow by abnormal promyelocytes and myelocytes, a low plasma fibrinogen, and defective coagulation.
adult T-cell l. (ATL) SYN: adult T-cell lymphoma.
aleukemic l. l. in which abnormal (or leukemic) cells are absent in the peripheral blood.
basophilic l., basophilocytic l. a form of granulocytic l. in which there are unusually great numbers of basophilic granulocytes in the tissues and circulating blood; in some instances, the immature and mature basophilic forms may represent from 40 to 80% of the total numbers of white blood cells. SYN: mast cell l..
chronic granulocytic l. SYN: chronic myelocytic l..
chronic myelocytic l. a heterogeneous group of myeloproliferative disorders that may evolve into acute l. in late stages ( i.e., blast crisis.) SYN: chronic granulocytic l., chronic myelogenous l., chronic myeloid l..
chronic myelogenous l. (CML) SYN: chronic myelocytic l..
chronic myeloid l. SYN: chronic myelocytic l..
l. cutis yellow-brown, red, blue-red, or purple, sometimes nodular lesions associated with diffuse infiltration of leukemic cells in the skin; the involvement may be diffuse and generalized, i.e., so-called universal l. cutis, or it may be localized.
embryonal l. SYN: stem cell l..
eosinophilic l., eosinophilocytic l. a form of granulocytic l. in which there are conspicuous numbers of eosinophilic granulocytes in the tissues and circulating blood, or in which such cells are predominant; in chronic disease of this type, the total white blood cell count may be as high as 200,000–250,000 per mm³, with as many as 80 or 90% being eosinophils, chiefly adult forms.
granulocytic l. a form of l. characterized by an uncontrolled proliferation of myelopoietic cells in the bone marrow and in extramedullary sites, and the presence of large numbers of immature and mature granulocytic forms in various tissues (and organs) and in the circulating blood; the total count may range from 1000 (aleukemic variety) to several hundred thousand per cu mm. The predominant cell is usually of the neutrophilic series, but, in a few instances, eosinophilic or basophilic granulocytes, or even megakaryocytes, may represent the chief form; early in granulocytic l., the circulating blood may contain excessive numbers of all of the granulocytic forms. SYN: leukemic myelosis (1) , myelocytic l., myelogenic l., myelogenous l., myeloid l..
hairy cell l. a rare, usually chronic disorder characterized by proliferation of hairy cells in reticuloendothelial organs and blood.
leukemic l. an obsolete redundant term sometimes used to emphasize the occurrence of abundant numbers of leukemic cells in the circulating blood; this classic form of l. is usually termed simply l..
leukopenic l. a form of lymphocytic, granulocytic, or monocytic l. in which the total number of white blood cells in the circulating blood is in the normal range, or may be diminished to various levels that are significantly less than normal.
lymphatic l. SYN: lymphocytic l..
lymphoblastic l. acute lymphocytic l. in which the abnormal cells are chiefly (or almost totally) blast forms of the lymphocytic series, or in which unusually large numbers of the immature forms occur in association with adult lymphocytes.
lymphocytic l. a variety of l. characterized by an uncontrolled proliferation and conspicuous enlargement of lymphoid tissue in various sites ( e.g., lymph nodes, spleen, bone marrow, lungs), and the occurrence of increased numbers of cells of the lymphocytic series in the circulating blood and in various tissues and organs; in chronic disease, the cells are adult lymphocytes, whereas conspicuous numbers of lymphoblasts are observed in the more acute syndromes. SYN: lymphatic l., lymphoid l..
lymphoid l. SYN: lymphocytic l..
mast cell l. SYN: basophilic l..
mature cell l. chronic granulocytic l..
megakaryocytic l. an unusual form of myelopoietic disease that is characterized by a seemingly uncontrolled proliferation of megakaryocytes in the bone marrow, and sometimes by the presence of a considerable number of megakaryocytes in the circulating blood. When bone marrow is examined at various intervals in some instances of chronic myelocytic l., the proliferation of megakaryocytes is more prominent than that of the granulocytes; at such times, the circulating blood may contain megakaryocytes or fragments of megakaryocytic nuclei and cytoplasm, or both, amounting to as much as 5 or 6% of the total number of leukocytes.
meningeal l. infiltration of the meninges by leukemic cells, a common occurrence in relapse following systemic administration of chemotherapeutic agents to l. patients.
micromyeloblastic l. a form of myelocytic l. in which relatively large proportions of micromyeloblasts are found in the circulating blood and in bone marrow and other tissues.
mixed l., mixed cell l. term infrequently used as a designation for granulocytic l., thereby emphasizing the occurrence of different types of cells in the myeloid series ( i.e., neutrophilic, eosinophilic, and basophilic granulocytes), in contrast to the comparatively monotonous pattern observed in lymphocytic and monocytic l..
monocytic l. a form of l. characterized by large numbers of cells that can be definitely identified as monocytes, in addition to larger, apparently related cells formed from the uncontrolled proliferation of the reticuloendothelial tissue; l. in which these two types of cells seem to “overrun” the usual sites of the reticuloendothelial system, and occur in conspicuous numbers in the circulating blood, is frequently referred to as the Schilling type of monocytic l., or sometimes as true monocytic l. The disease runs an acute or subacute course in older persons, and is characterized by swelling of gums, oral ulceration, bleeding in skin or mucous membranes, secondary infection, and splenomegaly.
murine l. a leukemic disorder of mice caused by a number of different type C retroviruses.
myeloblastic l. a form of granulocytic l. in which there are large numbers of myeloblasts in various tissues (and organs) and in the circulating blood; the immature forms may amount to 30–60% (or even a greater proportion) of the increased total number of white blood cells. Used synonymously with acute granulocytic l.. SYN: leukemic myelosis (2) .
myelocytic l., myelogenic l., myelogenous l., myeloid l. SYN: granulocytic l..
myelomonocytic l. a variant of granulocytic l. with monocytosis in the peripheral blood. SYN: Naegeli type of monocytic l..
Naegeli type of monocytic l. SYN: myelomonocytic l..
natural killer cell l. a l. originating from cells of natural killer cell origin; often associated with the presence of monoclonal Epstein-Barr virus infecting tumor cells; usually indicates a leukemic subtype of poor prognosis.
neutrophilic l. an unusual form of chronic granulocytic l. in which the greatly increased number of leukocytes in the circulating blood are mature polymorphonuclear neutrophils, with virtually no young or immature granulocytes being observed.
plasma cell l. an unusual disease characterized by leukocytosis and other signs and symptoms that are suggestive of l., in association with diffuse infiltrations and aggregates of plasma cells in the spleen, liver, bone marrow, and lymph nodes, and the presence of considerable numbers of plasma cells in the circulating blood; the total number of leukocytes in the latter may range from normal levels to 80,000 or 90,000/mm³, and 5–90% may be plasma cells; multiple myelomas are observed in some examples of plasma cell l., but discrete nodules are not formed in bone. Although there are other clinicopathologic differences in the two conditions, they may be phases of the same basic process.
polymorphocytic l. granulocytic l., especially any variety in which the predominant cells are mature, segmented granulocytes.
Rieder cell l. a special form of acute granulocytic l. in which the affected tissues and the circulating blood contain relatively large numbers of atypical myeloblasts ( i.e., Rieder cells) that have the usual, faintly granular, immature type of cytoplasm, and a bizarre, comparatively mature nucleus with several wide and deep indentations (suggestive of lobulation).
Schilling type of monocytic l. monocytic l..
splenic l. a form of l. in which there is an unusually great degree of enlargement of the spleen, as observed frequently in chronic granulocytic l..
stem cell l. a form of l. in which the abnormal cells are thought to be the precursors of lymphoblasts, myeloblasts, or monoblasts. SYN: embryonal l..
subleukemic l. a form of l. in which abnormal cells are present in the peripheral blood, but the total leukocyte count is not elevated. SYN: hypoleukemia, leukopenic myelosis, subleukemic myelosis, subleukemia.

leukemic
leukemic (loo-ke′mik)

Pertaining to, or having the characteristics of, any form of leukemia.

leukemid
leukemid (loo-kem′id)

Any nonspecific type of cutaneous lesion that is frequently associated with leukemia, but is not a localized accumulation of leukemic cells; e.g., petechiae, vesicles, wheals, bullae, hematomas, and the lesions of exfoliative dermatitis and herpes zoster. [leuko- + G. haima, blood, + id (1)]

leukemogen
leukemogen (loo-ke′mo-jen)

Any substance or entity ( e.g., benzene, ionizing radiation) considered to be a causal factor in the occurrence of leukemia.

leukemogenesis
leukemogenesis (loo-ke-mo-jen′e-sis)

The causation (or induction), development, and progression of a leukemic disease. [leukemia + G. genesis, production]

leukemogenic
leukemogenic (loo-ke-mo-jen′ik)

Pertaining to the causation, induction, and development of leukemia; manifesting the ability to cause leukemia.

leukemoid
leukemoid (loo-ke′moyd)

Resembling leukemia in various signs and symptoms, especially with reference to changes in the circulating blood. SEE ALSO: l. reaction. [leukemia + G. eidos, resemblance]

leukemoid reaction
leukemoid reaction

A moderate, advanced, or sometimes extreme degree of leukocytosis in the circulating blood, similar to that occurring in various forms of leukemia, but not the result of leukemic disease; usually, there is a disproportionate increase in the number of forms (including immature stages) in one series of leukocytes, and various examples of myelocytic, lymphocytic, monocytic, or plasmocytic l. may be also indistinguishable from leukocytosis that is associated with certain forms of leukemia. Leukemoid reactions are sometimes observed as a feature of: 1) infectious disease caused by certain bacteria and other biologic agents, e.g., tuberculosis, diphtheria, and chickenpox; 2) intoxication of various types, e.g., eclampsia, serious burns, and mustard gas poisoning; 3) malignant neoplasms, e.g., carcinoma of the colon, of the lung, of the kidney, or of other organs; 4) acute hemorrhage or hemolysis.
lymphocytic l. leukocytosis of varying degree, with adult lymphocytes and immature forms amounting to 40% (or more) of the total number of white blood cells in the circulating blood; may be observed in association with pertussis, infectious mononucleosis, gonorrhea, chickenpox, and sarcoidosis.
monocytic l. leukocytosis of varying degree, e.g., 30,000–40,000/mm³, with adult monocytes and immature forms amounting to 30% (or more) of the total number of white blood cells in the circulating blood; may be observed in association with tuberculosis, especially the first infection, miliary type.
myelocytic l. leukocytosis of at least moderate degree, e.g., 50,000 or more per mm³, with a few immature forms, e.g., 1 or 2% myelocytes, but chiefly mature polymorphonuclear leukocytes in the circulating blood; may be observed in association with tuberculosis, chronic osteomyelitis, various types of empyema, malaria, pneumococcal pneumonia, meningococcal meningitis, Hodgkin disease, and metastases of carcinoma in the bone marrow.
plasmocytic l. the presence of unusual numbers of plasma cells, i.e., plasmocytosis, in the bone marrow; may be observed in association with sarcoidosis, rheumatoid arthritis, cirrhosis, Hodgkin disease, and certain of the so-called vascular collagen diseases.

leukin
leukin (loo′kin)

A thermostable bactericidal substance extracted from leukocytes. SYN: leucin. [leukocyte + -in]

leuko- leuko-, leuk-

White; white blood cells. For some words beginning thus, see leuc- and leuco-. [G. leukos, white]

leukoagglutinin
leukoagglutinin (loo′ko-a-gloo′ti-nin)

An antibody that agglutinates white blood cells.

leukobilin
leukobilin (loo-ko-bil′in)

SYN: white bile. [leuko- + L. bilis, bile]

leukoblast
leukoblast (loo′ko-blast)

An immature granular leukocyte. SYN: proleukocyte. [leuko- + G. blastos, germ]

leukoblastosis
leukoblastosis (loo′ko-blas-to′sis)

A general term for the abnormal proliferation of leukocytes, especially that occurring in myelocytic and lymphocytic leukemia.

leukochloroma
leukochloroma (loo′ko-klo-ro′ma)

Obsolete term for myelocytomatosis. [leuko- + G. chloros, green, + -oma, tumor]

leukocidin
leukocidin (loo-kos′i-din, loo-ko-si′din)

A heat-labile substance that is elaborated by many strains of Staphylococcus aureus, Streptococcus pyogenes, and pneumococci and manifests a destructive action on leukocytes, with or without lysis of the cells. [leukocyte + L. caedo, to kill]

leukocoria
leukocoria, leukokoria (loo-ko-ko′re-a, loo-ko-ko′re-a)

Reflection from a white mass within the eye giving the appearance of a white pupil. SYN: leukokoria, white pupillary reflex. [leuko- white, + G. kore, pupil]

leukocytactic
leukocytactic (loo′ko-si-tak′tik)

SYN: leukocytotactic.

leukocytal
leukocytal (loo-ko-si′tal)

SYN: leukocytic.

leukocytaxia
leukocytaxia, leukocytaxis (loo′ko-si-tak′se-a, -tak′sis)

SYN: leukocytotaxia.

leukocyte
leukocyte (loo′ko-sit)

A type of cell formed in the myelopoietic, lymphoid, and reticular portions of the reticuloendothelial system in various parts of the body, and normally present in those sites and in the circulating blood (rarely in other tissues). Under various abnormal conditions, the total numbers or proportions, or both, may be characteristically increased, decreased, or not altered, and they may be present in other tissues and organs. Leukocytes represent three lines of development from primitive elements: myeloid, lymphoid, and monocytic series. On the basis of features observed with various methods of staining with polychromatic dyes ( e.g., Wright stain). cells of the myeloid series are frequently termed granular leukocytes, or granulocytes; cells of the lymphoid and monocytic series also have granules in the cytoplasm but, owing to their tiny, inconspicuous size and different properties (frequently not clearly visualized with routine methods), lymphocytes and monocytes are sometimes termed nongranular or agranular leukocytes. Granulocytes are commonly known as polymorphonuclear leukocytes (also polynuclear or multinuclear leukocytes), inasmuch as the mature nucleus is divided into two to five rounded or ovoid lobes that are connected with thin strands or small bands of chromatin; they consist of three distinct types: neutrophils, eosinophils, and basophils, named on the basis of the staining reactions of the cytoplasmic granules. Cells of the lymphocytic series occur as two, somewhat arbitrary, normal varieties: small and large lymphocytes; the former represent the ordinary forms and are conspicuously more numerous in the circulating blood and normal lymphoid tissue; the latter may be found in normal circulating blood, but are more easily observed in lymphoid tissue. The small lymphocytes have nuclei that are deeply or densely stained (the chromatin is coarse and bulky) and almost fill the cells, with only a slight rim of cytoplasm around the nuclei; the large lymphocytes have nuclei that are approximately the same size as, or only slightly larger than, those of the small forms, but there is a broader, easily visualized band of cytoplasm around the nuclei. Cells of the monocytic series are usually larger than the other leukocytes, and are characterized by a relatively abundant, slightly opaque, pale blue or blue-gray cytoplasm that contains myriad extremely fine reddish-blue granules. Monocytes are usually indented, reniform, or shaped similarly to a horseshoe, but are sometimes rounded or ovoid; their nuclei are usually large and centrally placed and, even when eccentrically located, are completely surrounded by at least a small band of cytoplasm. SYN: white blood cell. [leuko- + G. kytos, cell]
acidophilic l. SYN: eosinophilic l..
agranular l. SYN: nongranular l..
basophilic l. a polymorphonuclear l. characterized by many large, coarse, metachromatic granules (dark purple or blue-black when treated with Wright or similar stains) that usually fill the cytoplasm and may almost mask the nucleus; these leukocytes are unique in that they usually do not occur in increased numbers as the result of acute infectious disease, and their phagocytic qualities are probably not significant; the granules, which contain heparin and histamine, may degranulate in response to hypersensitivity reactions and can be of significance in general inflammation. SYN: basocyte, basophilocyte, mast l..
cystinotic l. a l. having an enhanced content of cystine, found in patients with disorders characterized by the storage of cystine; within the l., the cystine, largely in noncrystalline form, is associated with dense lysosomal particles.
endothelial l. obsolete term for a monocyte, a type of l. thought to be derived from reticuloendothelial tissue.
eosinophilic l. a polymorphonuclear l. characterized by many large or prominent, refractile, cytoplasmic granules that are fairly uniform in size and bright yellow-red or orange when treated with Wright or similar stains; the nuclei are usually larger than those of neutrophils, do not stain as deeply, and characteristically have two lobes (a third lobe is sometimes interposed on the connecting strand of chromatin); these leukocytes are motile phagocytes with distinctive antiparasitic functions. SYN: acidophilic l., eosinocyte, eosinophil, eosinophile, oxyphil (2) , oxyphile, oxyphilic l..
filament polymorphonuclear l. any mature polymorphonuclear l., especially a neutrophilic l., in which the lobes of the nucleus are interconnected with a thin strand or filament of chromatin.
globular l. a type of wandering cell with a small, round nucleus found in the epithelium and lamina propria of the intestinal mucosa of many animals; its cytoplasm contains large eosinophilic globules or droplets.
granular l. any one of the polymorphonuclear leukocytes, especially a neutrophilic l.. SEE ALSO: granulocyte, basophilic l., eosinophilic l..
hyaline l. obsolete term for a monocyte, and for a mononuclear macrophage in various lesions.
mast l. SYN: basophilic l..
motile l. any l. that manifests active ameboid movement, especially a mature granulocytic l. (eosinophils are less motile than neutrophils or basophils); monocytes manifest a slow, but persistent, wavelike movement.
multinuclear l. SYN: polymorphonuclear l..
neutrophilic l. a neutrophilic granulocyte, the most frequent of the polymorphonuclear leukocytes, and also the most active phagocyte among the various types of white blood cells; when treated with Wright stain (or similar preparations), the fairly abundant cytoplasm is faintly pink, and numerous tiny, slightly refractile, relatively bright pink or violet-pink, diffusely scattered granules are recognizable in the cytoplasm; the deeply stained blue or purple-blue nucleus is sharply distinguished from the cytoplasm and is distinctly lobated, with thin strands of chromatin connecting the three to five lobes.
nonfilament polymorphonuclear l. a neutrophil, basophil, or eosinophil that is not completely matured, i.e., the lobes of the nuclei remain connected with bands of chromatin, in contrast to the thin strands observed in mature cells.
nongranular l. a general, nonspecific term frequently used with reference to lymphocytes, monocytes, and plasma cells; although the cytoplasm of a lymphocyte or monocyte contains tiny granules, it is “nongranular” in comparison with that of a neutrophil, basophil, or eosinophil. SEE ALSO: l.. SYN: agranular l..
nonmotile l. a term sometimes used with reference to lymphocytes, monocytes, and plasma cells; although such forms actually have some degree of motility, they are “nonmotile” in comparison with the actively ameboid neutrophilic, basophilic, and eosinophilic leukocytes.
oxyphilic l. SYN: eosinophilic l..
polymorphonuclear l., polynuclear l. common term for granulocyte or granulocytic l.; the term includes basophilic, eosinophilic, and neutrophilic leukocytes, but is usually used especially with reference to the neutrophilic leukocytes. SYN: multinuclear l..
segmented l. any mature polymorphonuclear l., especially a neutrophilic l..
transitional l. obsolete term for a monocyte.
Türk l. SYN: Türk cell.

leukocythemia
leukocythemia (loo′ko-si-the′me-a)

Obsolete term for leukemia. [leukocyte + G. haima, blood]

leukocytic
leukocytic (loo-ko-sit′ik)

Pertaining to or characterized by leukocytes. SYN: leukocytal.

leukocytoblast
leukocytoblast (loo-ko-si′to-blast)

A nonspecific term for any immature cell from which a leukocyte develops, including lymphoblast, myeloblast, and the like. [leukocyte + G. blastos, germ]

leukocytoclasis
leukocytoclasis (loo′ko-si-tok′la-sis)

Karyorrhexis of leukocytes. [leuko- + G. kytos, cell, + klasia, a breaking]

leukocytogenesis
leukocytogenesis (loo′ko-si-to-jen′e-sis)

The formation and development of leukocytes. [leukocyte + G. genesis, production]

leukocytoid
leukocytoid (loo′ko-si-toyd)

Resembling a leukocyte. [leukocyte + G. eidos, resemblance]

leukocytolysin
leukocytolysin (loo′ko-si-tol′i-sin)

Any substance (including lytic antibody) that causes dissolution of leukocytes. SYN: leukolysin.

leukocytolysis
leukocytolysis (loo′ko-si-tol′i-sis)

Dissolution or lysis of leukocytes. SYN: leukolysis. [leukocyte + G. lysis, dissolution]

leukocytolytic
leukocytolytic (loo′ko-si-to-lit′ik)

Pertaining to, causing, or manifesting leukocytolysis. SYN: leukolytic.

leukocytoma
leukocytoma (loo′ko-si-to′ma)

Obsolete term for a fairly well circumscribed, nodular, dense accumulation of leukocytes. [leukocyte + G. -oma, tumor]

leukocytometer
leukocytometer (loo′ko-si-tom′e-ter)

A standardized glass slide that is suitably ruled for counting the leukocytes in a measured volume of accurately diluted blood (or other specimens). [leukocyte + G. metron, measure]

leukocytopenia
leukocytopenia (loo′ko-si-to-pe′ne-a)

SYN: leukopenia.

leukocytoplania
leukocytoplania (loo′ko-si-to-pla′ne-a)

Movement of leukocytes from the lumens of blood vessels, through serous membranes, or in the tissues. [leukocyte + G. plane, a wandering]

leukocytopoiesis
leukocytopoiesis (loo′ko-si-to-poy-e′sis)

SYN: leukopoiesis. [leukocyte + G. poiesis, a making]

leukocytosis
leukocytosis (loo′ko-si-to′sis)

An abnormally large number of leukocytes, as observed in acute infections, inflammation, hemorrhage, and other conditions. A white blood cell count of 10,000 or more per mm³ usually indicates l. Most examples of l. represent a disproportionate increase in the number of cells in the neutrophilic series, and the term is frequently used synonymously with the designation neutrophilia. L. of 15,000–25,000/mm³ is frequently observed in various pathologic conditions, and values as high as 40,000 are not unusual; occasionally, as in some examples of leukemoid reactions, white blood cell counts may range up to 100,000/mm³. [leukocyte + G. -osis, condition]
absolute l. an actual increase in the total number of leukocytes in the circulating blood, as distinguished from a relative increase (such as that observed in dehydration).
agonal l. SYN: terminal l..
basophilic l. the presence of an abnormally large number of basophilic granulocytes in the blood. SYN: basocytosis.
digestive l. l. occurring normally after ingestion of food.
distribution l. an abnormally large proportion of one or more types of leukocytes.
emotional l. an abnormally high white blood cell count that is thought to be related only to an emotional disturbance.
eosinophilic l. a form of relative l. in which the greatest proportionate increase is in the eosinophils. SYN: eosinophilia.
lymphocytic l. SYN: lymphocytosis.
monocytic l. SYN: monocytosis.
neutrophilic l. SYN: neutrophilia.
l. of the newborn an apparently “physiologic” l. usually observed in newborn infants, in whom the white blood cell counts are usually greater than 10,000/mm³, and sometimes range to 45,000/mm³, resulting chiefly from increased numbers of neutrophils (especially single and bilobed forms). On the third or fourth day of life, the count generally decreases rapidly, and then fluctuates for several days; beginning about the fourth week of life, a relative lymphocytosis is observed, and this normally continues for a few years.
physiologic l. any form of l. that is associated with apparently normal situations and that is not directly related to a pathologic condition; e.g., the temporary increase in the total number of white blood cells that may occur during a single day, or from day to day, as well as in the newborn period, during childhood, after strenuous exercise, during attacks of paroxysmal tachycardia, and in association with various other situations.
relative l. an increased proportion of one or more types of leukocytes in the circulating blood, without an actual increase in the total number of white blood cells.
terminal l. one that occurs in a person just prior to death, especially in one who has a “slow death.” SYN: agonal l..

leukocytotactic
leukocytotactic (loo′ko-si-to-tak′tik)

Pertaining to, characterized by, or causing leukocytotaxia. SYN: leukocytactic, leukotactic.

leukocytotaxia
leukocytotaxia (loo-ko-si-to-tak′se-a)

1. The active ameboid movement of leukocytes, especially the neutrophilic granulocytes, either toward (positive l.) or away from (negative l.) certain microorganisms as well as various substances frequently formed in inflamed tissue. 2. The property of attracting or repelling leukocytes. SYN: leukocytaxia, leukocytaxis, leukotaxia, leukotaxis. [leukocyte + G. taxis, arrangement]

leukocytotoxin
leukocytotoxin (loo′ko-si-to-tok′sin)

Any substance that causes degeneration and necrosis of leukocytes, including leukolysin and leukocidin. SYN: leukotoxin. [leukocyte + G. toxikon, poison]

leukocyturia
leukocyturia (loo′ko-si-too′re-a)

The presence of leukocytes in urine that is recently voided or collected by means of a catheter. [leukocyte + G. ouron, urine]

leukoderma
leukoderma (loo-ko-der′ma)

An absence of pigment, partial or total, in the skin. SYN: hypomelanosis, leukopathia, leukopathy. [leuko- + G. derma, skin]
acquired l. SYN: vitiligo.
l. acquisitum centrifugum SYN: halo nevus.
l. colli SYN: syphilitic l..
syphilitic l. a fading of the roseola of secondary syphilis, leaving reticulated depigmented and hyperpigmented areas located chiefly on the sides of the neck. SYN: l. colli, melanoleukoderma colli.

leukodermatous
leukodermatous (loo-ko-der′ma-tus)

Relating to or resembling leukoderma.

leukodontia
leukodontia (loo-ko-don′she-a)

The condition of having white teeth. [leuko- + G. odous, tooth]

leukodystrophia
leukodystrophia (loo-ko-dis-tro′fe-a)

SYN: leukodystrophy.
l. cerebri progressiva SYN: leukodystrophy.

leukodystrophy
leukodystrophy (loo-ko-dis′tro-fe)

Term for a group of white matter diseases, some familial, characterized by progressive cerebral deterioration usually in early life, and pathologically by primary absence or degeneration of the myelin of the central and peripheral nervous systems with glial reaction; probably related to a defect in lipid metabolism; most leukodystrophies are autosomal recessive, several X-linked recessive, and a few autosomal dominant. SEE ALSO: Canavan disease. SYN: leukodystrophia cerebri progressiva, leukodystrophia, sclerosis of white matter. [leuko- + G. dys, bad, + trophe, nourishment]
adrenal l. sudanophilic l. with bronzing of skin and adrenal atrophy. A metabolic disorder of young males, characterized by widespread myelin degeneration and associated adrenal insufficiency. The myelin degeneration is massive in various portions of the brain and sometimes the spinal cord, with the accumulation of degradation products of myelin in macrophages: sudanophilic demyelination; atrophy is present in the adrenal glands and testes, and markedly increased amounts of very long-chain fatty acid are present in both the brain and adrenal glands. Symptoms include bronzing of the skin, dysarthria, cortical blindness, bilateral hemiplegia, pseudobulbar paralysis, and progressive dementia. Probably sex-linked recessive inheritance.
globoid cell l. [MIM*245200] a metabolic disorder of infancy or early childhood characterized by spasticity, seizures, and rapidly progressive cerebral degeneration, massive loss of myelin, severe astrocytic gliosis, and infiltration of the white matter with characteristic multinucleate globoid cells; metabolically there is gross deficiency of lysosomal cerebrosidase (galactosylceramide β-galactosidase); autosomal recessive inheritance, caused by mutation in the gene encoding glycosylceramidase (GALC) on 14q. SYN: diffuse infantile familial sclerosis, galactosylceramide lipoidosis, Krabbe disease.
metachromatic l. [MIM*250100] a metabolic disorder, with onset usually in the second year of life and death often before 5 years, with loss of myelin and accumulation of metachromatic lipids (galactosyl sulfatidates) in the white matter of the central and peripheral nervous systems leading to motor symptoms, paralysis, convulsions, and progressive cerebral deterioration;. Autosomal recessive inheritance [MIM*249900 and MIM*250100], caused by mutation in either the arylsulfatase A gene (ARSA) on 22q or the prosaposin gene (PSAP) on 10q. There is a dominant form occurring in adults [MIM*156310]. SYN: arylsulfatase A deficiency, sulfatide lipidosis.
l. with diffuse Rosenthal fiber formation a metabolic disorder whose onset can be in infancy, adolescence, or adulthood; characterized pathologically by widespread cerebral demyelination with astrocyte and primitive oligodendroglial cell proliferation; refractile Rosenthal fibers result from the degeneration of these proliferating cells; etiology unknown, but possibly due to a metabolic defect of astrocytes; sex-linked recessive disorder.

leukoencephalitis
leukoencephalitis (loo′ko-en-sef-a-li′tis)

Encephalitis restricted to the white matter.
acute epidemic l. a disease characterized by acute onset of fever, followed by convulsions, delirium, and coma, and associated with perivascular demyelination and hemorrhagic foci in the central nervous system. SYN: acute primary hemorrhagic meningoencephalitis, Strümpell disease (2) .
acute hemorrhagic l. SYN: acute necrotizing hemorrhagic encephalomyelitis.
acute necrotizing hemorrhagic l. SYN: acute necrotizing hemorrhagic encephalomyelitis.
sclerosing l. SYN: subacute sclerosing panencephalitis.
subacute sclerosing l. SYN: subacute sclerosing panencephalitis.

leukoencephalopathy
leukoencephalopathy (loo′ko-en-sef-a-lop′a-the)

White matter changes first described in children with leukemia, associated with radiation and chemotherapy injury, often associated with methotrexate; pathologically characterized by diffuse reactive astrocytosis with multiple areas of necrotic foci without inflammation. [leuko- + G. enkephalos, brain, + pathos, suffering]
progressive multifocal l. (PML) a rare, subacute, afebrile disease characterized by areas of demyelinization surrounded by markedly altered neuroglia, including inclusion bodies in glial cells; it occurs usually in individuals with AIDS, leukemia, lymphoma, or other debilitating diseases, or in those who have been receiving immunosuppressive treatment. Caused by JC virus, a human polyoma virus. SYN: progressive subcortical encephalopathy.

leukoerythroblastosis
leukoerythroblastosis (loo′ko-e-rith′ro-blas-to′sis)

Any anemic condition resulting from space-occupying lesions in the bone marrow; the circulating blood contains immature cells of the granulocytic series and nucleated red blood cells, frequently in numbers that are disproportionately large in relation to the degree of anemia. SYN: leukoerythroblastic anemia, myelophthisic anemia, myelopathic anemia.

leukokinetic
leukokinetic (loo′ko-ki-net′ik)

Pertaining to leukokinetics. [leukocyte + G. kinetikos, of motion, fr. kineo, to move]

leukokinetics
leukokinetics (loo′ko-ki-net′iks)

The study of the formation, circulation, and fate of leukocytes, usually by use of a radioactive tracer. [leukocyte + G. kinetikos, of or for putting in motion]

leukokoria
leukokoria (loo-ko-ko′re-a)

See leukocoria.

leukokraurosis
leukokraurosis (loo′ko-kraw-ro′sis)

SYN: kraurosis vulvae.

leukolysin
leukolysin (loo-kol′i-sin)

SYN: leukocytolysin.

leukolysis
leukolysis (loo-kol′i-sis)

SYN: leukocytolysis.

leukolytic
leukolytic (loo-ko-lit′ik)

SYN: leukocytolytic.

leukoma
leukoma (loo-ko′ma)

A dense white opacity of the cornea. [G. whiteness, a white spot in the eye, fr. leukos, white]
adherent l. a cicatrix of the cornea to which a portion of the iris is attached.

leukomatous
leukomatous (loo-ko′ma-tus)

Pertaining to leukoma.

leukomyelitis
leukomyelitis (loo′ko-mi-e-li′tis)

An inflammatory process involving the white matter of the spinal cord.
necrotizing hemorrhage l. the pathological substrate responsible for the clinical disorder of acute necrotizing myelitis.

leukomyelopathy
leukomyelopathy (loo′ko-mi′e-lop′a-the)

Any systemic disease involving the white matter or the conducting tracts of the spinal cord. [leuko- + G. myelos, marrow, + pathos, suffering]

leukon
leukon (loo′kon)

The total mass of circulating leukocytes as well as the cells and leukopoietic cells from which it originates.

leukonecrosis
leukonecrosis (loo′ko-ne-kro′sis)

SYN: white gangrene. [leuko- + G. nekrosis, deadness]

leukonychia
leukonychia (loo-ko-nik′e-a)

The occurrence of smooth-surfaced white spots or patches under the nails, of unknown cause; the decoloration may be total or in the form of lines (striate or transverse l.) or dots (punctate l.). [leuko- + G. onyx (onych-), nail]

leukopathia
leukopathia, leukopathy (loo-ko-path′e-a, loo-kop′a-the)

SYN: leukoderma. [leuko- + G. pathos, disease]

leukopedesis
leukopedesis (loo′ko-pe-de′sis)

The movement of white blood cells (especially polymorphonuclear leukocytes) through the walls of capillaries and into the tissues. [leuko- + G. pedesis, a leaping]

leukopenia
leukopenia (loo-ko-pe′ne-a)

The antithesis of leukocytosis; any situation in which the total number of leukocytes in the circulating blood is less than normal, the lower limit of which is generally regarded as 4000–5000/mm³. SYN: leukocytopenia. [leuko(cyte) + G. penia, poverty]
basophilic l. a decrease in the number of basophilic granulocytes in the circulating blood (difficult to evaluate, owing to the small and variable number normally present). SYN: basocytopenia, basopenia.
eosinophilic l. a decrease in the number of eosinophilic granulocytes normally present in the circulating blood.
lymphocytic l. SYN: lymphopenia.
monocytic l. SYN: monocytopenia.
neutrophilic l. SYN: neutropenia.

leukopenic
leukopenic (loo-ko-pe′nik)

Pertaining to leukopenia.

leukoplakia
leukoplakia (loo-ko-pla′ke-a)

A white patch of oral or female genital mucous membrane that cannot be wiped off and cannot be diagnosed clinically as any specific disease entity; in current usage, a clinical term without histologic connotation. SYN: smoker's patches. [leuko- + G. plax, plate]
hairy l. a white lesion appearing on the tongue, occasionally on the buccal mucosa, of patients with AIDS; a manifestation of Epstein-Barr virus infection in an immunocompromised host; the lesion appears raised, with a corrugated, shaggy, or “hairy” surface due to keratin projections.Oral hairy l. was first recognized in 1981 as a marker of immunosuppression in male homosexuals with AIDS. The incidence in persons with AIDS is about 20%. Oral hairy l. consists of white vertical folds or ridges, generally along the lateral borders of the tongue, but sometimes on its lower surface or on the buccal mucosa. Unlike the lesions of candidiasis (thrush), the patches cannot be scraped off. The condition is ordinarily asymptomatic, causing neither pain nor alteration of taste. Histologic study shows parakeratosis and koilocytosis with little inflammation. The lesion occasionally progresses to squamous cell carcinoma. Treatment with topical podophyllin or systemic acyclovir usually induces prompt regression of lesions.
l. vulvae a clinical term for hyperkeratotic white patches of the vulvar epithelium; biopsy is necessary for specific diagnosis.

leukopoiesis
leukopoiesis (loo′ko-poy-e′sis)

Formation and development of the various types of white blood cells. SYN: leukocytopoiesis. [leuko- + G. poiesis, a making]

leukopoietic
leukopoietic (loo′ko-poy-et′ik)

Pertaining to or characterized by leukopoiesis, as manifested by portions of the bone marrow and reticuloendothelial and lymphoid tissues, which form (respectively) the granulocytes, monocytes, and lymphocytes.

leukoprotease
leukoprotease (loo-ko-pro′te-as)

An ill-defined proteolytic enzyme product of polynuclear leukocytes, formed in an area of inflammation, that causes liquefaction of dead tissue.

leukoriboflavin
leukoriboflavin (loo-ko-ri′bo-fla-vin)

The colorless nonfluorescing dihydro compound formed by the reduction of riboflavin.

leukorrhagia
leukorrhagia (loo-ko-ra′je-a)

SYN: leukorrhea. [leuko- + G. rhegnymi, to burst forth]

leukorrhea
leukorrhea (loo-ko-re′a)

Discharge from the vagina of a white or yellowish viscid fluid containing mucus and pus cells. SYN: leukorrhagia. [leuko- + G. rhoia, flow]
menstrual l. intermittent l. recurring at or just before each menstrual period.

leukorrheal
leukorrheal (loo-ko-re′al)

Relating to or characterized by leukorrhea.

leukotactic
leukotactic (loo-ko-tak′tik)

SYN: leukocytotactic.

leukotaxia
leukotaxia (loo-ko-tak′se-a)

SYN: leukocytotaxia.

leukotaxine
leukotaxine (loo-ko-tak′sen)

A cell-free nitrogenous material prepared from injured, acutely degenerating tissue and from inflammatory exudates.

leukotaxis
leukotaxis (loo-ko-tak′sis)

SYN: leukocytotaxia.

leukotome
leukotome (loo′ko-tom)

An instrument for performing leukotomy.

leukotomy
leukotomy (loo-kot′o-me)

Incision into the white matter of the frontal lobe of the brain. [leuko- + G. tome, a cutting]
prefrontal l. SYN: prefrontal lobotomy.
transorbital l. SYN: transorbital lobotomy.

leukotoxin
leukotoxin (loo-ko-tok′sin)

SYN: leukocytotoxin.

leukotrichia
leukotrichia (loo-ko-trik′e-a)

Whiteness of the hair. [leuko- + G. thrix, hair]

leukotrienes
leukotrienes (LT) (loo-ko-tri′enz)

Products of eicosanoid metabolism (usually, arachidonic acid) with postulated physiologic activity such as mediators of inflammation and roles in allergic reactions; they differ from the related prostaglandins and thromboxanes by not having a central ring; so named because they were originally discovered in association with leukocytes and of three conjugated double bonds; letters A through F identify the first six metabolites isolated, with subscript numbers to indicate the number of double bonds ( e.g., leukotriene C₄).
peptidyl l. l. having one or more amino acids present; e.g., LTC₄ is an S-substituted glutathione, LTD₄ is an S-substituted cysteinylglycine, LTE₄ is an S-substituted cysteine, and LTF₄ (also known as γ-glutamyl-LTE₄) is an S-substituted γ-glutamylcysteine.

Leukovirus
Leukovirus (loo′ko-vi′rus)

Obsolete term for a former genus composed of the RNA tumor viruses now included in the family Retroviridae.

LEU M1
LEU M1

The epitope for a monoclonal antibody generated to the human histiocytic cell line that localizes to neutrophils, adherent monocytes, and a subgroup of activated T cells.

leupeptin
leupeptin (loo-pep′tin)

One of a number of modified tripeptide protease inhibitors from Streptomyces species that inhibits cathepsin B, papain, trypsin, plasmin, and cathepsin D. The most commonly used l. is N-acetylleucylleucylarginal.

leuprolide acetate
leuprolide acetate (loo′pro-lid)

A synthetic nonapeptide analog of naturally occurring gonadotropin-releasing hormone; used in the palliative treatment of advanced prostatic cancer.

leurocristine
leurocristine (loo′ro-kris′tin)

SYN: vincristine sulfate.

Lev
Lev

Maurice, U.S. pathologist, 1908–1994. See L. disease, L. syndrome.

Levaditi
Levaditi

Constantin, Romanian bacteriologist in Paris, 1879–1928. See L. stain.

levallorphan tartrate
levallorphan tartrate (lev-a-lor′fan)

The N-allyl analog of levorphanol, antagonistic to the actions of narcotic analgesics; used in the treatment of respiratory depression due to overdosage of narcotics.

levamisole
levamisole (le-vam′i-sol)

Formerly used as an anthelmintic; increases immune responses and is used adjunctively with antineoplastic agents to improve response and suppress recurrence.

levan
levan (le′van)

SYN: fructosan (1) .

levansucrase
levansucrase (lev-an-soo′kras)

An enzyme catalyzing transfer of the fructose moiety of sucrose to polyfructose (a levan), releasing d-glucose.

levarterenol
levarterenol (lev-ar-ter′e-nol)

SYN: norepinephrine.
l. bitartrate SYN: norepinephrine bitartrate.

levator
levator (le-va′ter, tor) [TA]

1. A surgical instrument for prying up the depressed part in a fracture of the skull. 2. One of several muscles whose action is to raise the part to which it inserts. [L. a lifter, fr. levo, pp. -atus, to lift, fr. levis, light]

LeVeen
LeVeen

Harry H., U.S. surgeon, *1914. See L. shunt.

level
level (le′vel)

1. Any rank, position, or status in a graded scale of values. 2. A test for determining such rank or position.
acoustic reference l. the biological reference l. for sound measurements. When the term decibel is used to indicate the noise l., a reference quantity is implied; this reference value is usually expressed as a sound pressure of 20 micronewtons per square meter. The reference l. is referred to as 0 decibels, the baseline of the scale of noise levels; this baseline is considered the weakest sound that can be heard by a person with very good hearing in an extremely quiet location. Other equivalent reference levels still being used include 0.0002 microbar and 0.0002 dyne per square centimeter. SEE ALSO: sound pressure l..
l. of aspiration in clinical psychology, the degree or quality of performance (exhibited in a testing situation) which a person desires to attain or feels he or she can achieve.
background l. the concentration (usually low) at which a substance or agent is present or occurs at a particular time and place in the absence of a specific hazard under investigation; an example is the background l. of ionizing radiation.
Clark l. the l. of invasion of primary malignant melanoma of the skin; limited to the epidermis, I; into the underlying papillary dermis, II; to the junction of the papillary and reticular dermis, III; into the reticular dermis, IV; into the subcutaneous fat, V. The prognosis is worse with each successive deeper l. of invasion.
hearing l. the measure of the status of hearing as read directly on the hearing loss scale of an audiometer; described in decibels as a deviation from a standard value for zero on the audiometer.
loudness discomfort l. the intensity at which sound, particularly speech, causes discomfort.
most comfortable l. the greatest sound intensity that is comfortable.
saturation sound pressure l. (SSPL) a measure of the maximum output of a hearing aid.
sensation l. the amount in decibels that a stimulus is above the hearing threshold.
sensory acuity l. a technique for determining air conduction thresholds without masking and with masking presented by bone conduction to the forehead; the change in thresholds indicates the conductive hearing loss.
sound pressure l. (SPL) a measure of sound energy relative to 0.0002 dynes/cm², expressed in decibels.
uncomfortable l. the intensity of sound that causes discomfort.
window l. the CT number setting in Hounsfield units of the midpoint of the window width, which is the gray scale of the image; a typical window l. for imaging the lungs is −500; for the abdomen, 0.

Leventhal
Leventhal

Michael L., U.S. obstetrician-gynecologist, 1901–1971. See Stein-L. syndrome.

lever
lever (lev′er, le′ver)

An instrument used to lift or pry. [Fr. l., to lift]
dental l. SYN: elevator (2) .

leverage
leverage (le′ver-ij)

1. The actual lift or elevating direction of a lever or elevator. 2. The mechanical advantage gained thereby.

Levey
Levey

S., 20th century U.S. statistician. See L.-Jennings chart.

Lévi
Lévi

E. Leopold, French endocrinologist, 1868–1933. See dominantly inherited L. disease, Lorain-L. dwarfism, Lorain-L. infantilism, Lorain-L. syndrome.

Levin
Levin

Abraham, U.S. physician, 1880–1940. See L. tube.

Levin
Levin

Max, U.S. neurologist, *1901. See Kleine-L. syndrome.

Levine
Levine

Samuel A., U.S. cardiologist, 1891–1966. See Lown-Ganong-L. syndrome.

Levinea
Levinea (le-vin′e-a)

A former genus of bacteria (of the family Enterobacteriaceae) whose species are now assigned to the genus Citrobacter. [Max Levine, U.S. bacteriologist, *1889]
L. amalonatica SYN: Citrobacter amalonatica.
L. diversus SYN: Citrobacter diversus.
L. malonatica SYN: Citrobacter diversus.

levitation
levitation (lev-i-ta′shun)

Support of the patient on a cushion of air. [L. levitas, lightness]

Leviviridae
Leviviridae (le-vi-vir′i-de)

Provisional name for a family of small, nonenveloped, isometric bacterial viruses with genomes of single-stranded positive sense RNA (MW 1 × 10⁶). Virions adsorb to the sides of bacterial pili, and crystalline arrays are formed in infected bacteria. The type species is enterobacteria phage M52. [L. levis, light (not heavy)]

levo- levo-

Left, toward or on the left side. [L. laevus]

levobunolol hydrochloride
levobunolol hydrochloride (le-vo-bu′no-lol)

A β-adrenergic blocking agent used primarily as an eye drop in the treatment of chronic open-angle glaucoma and ocular hypertension.

levocardia
levocardia (le-vo-kar′de-a)

Situs inversus of the other viscera but with the heart normally situated on the left; congenital cardiac lesions are commonly associated. [levo- + G. kardia, heart]

levocardiogram
levocardiogram (le-vo-kar′de-o-gram)

That part of the electrocardiogram that is the effect of the left ventricle.

levocarnitine
levocarnitine (le′vo-kar′ni-ten)

Used as a supplement for carnitine deficiency.

levoclination
levoclination (le′vo-kli-na′shun)

SYN: levotorsion (2) . [levo- + L. clino, pp. -atus, to bend]

levocycleduction
levocycleduction

SYN: sinistrotorsion.

levocycloduction
levocycloduction (le′vo-si-klo-duk′shun)

levotorsion of one eye. [levo- + cyclo- + L. duco, pp. ductus, to lead]

levodopa
levodopa (le-vo-do′pa)

The biologically active form of dopa; an antiparkinsonian agent that is converted to dopamine. SYN: l-dopa.

levoduction
levoduction (le-vo-duk′shun)

Turning of one eye to the left; abduction of left eye or adduction of right eye. [levo- + L. duco, pp. ductus, to lead]

levoform
levoform (le′vo-form)

Denoting the structure of a substance that rotates the plane of polarized light counterclockwise (left); that is, as viewed by the observer looking toward the light source.

levoglucose
levoglucose (le-vo-gloo′kos)

d-Fructose. See fructose.

levogram
levogram (le′vo-gram)

Electrocardiographic record in an experimental animal representing spread of impulse through the left ventricle alone.

levogyrate
levogyrate, levogyrous (le-vo-ji′rat, -ji′rus)

SYN: levorotatory. [levo- + L. gyro, to turn in a circle]

levonordefrin
levonordefrin (le′vo-nor-def′rin)

Used as a nasal decongestant and as a vasoconstrictor given with infiltration anesthetics.

levophacetoperane
levophacetoperane (le′vo-fa-se-top′er′an)

An antidepressant with anorexigenic properties.

levophobia
levophobia (lev′o-fo′be-a)

Fear of objects to the left.

levopropoxyphene napsylate
levopropoxyphene napsylate (le′vo-pro-pok′si-fen)

An antitussive.

levorotation
levorotation (le-vo-ro-ta′shun)

1. A turning or twisting to the left; in particular, the counterclockwise twist given the plane of plane-polarized light by solutions of certain optically active substances. Cf.:dextrorotation. 2. SYN: sinistrotorsion. [levo- + L. roto, to turn]

levorotatory
levorotatory (le-vo-ro′ta-tor-e)

1. Denoting levorotation, or certain crystals or solutions capable of causing it; as a chemical prefix, usually abbreviated l- or (−). Cf.:dextrorotatory. 2. Describing any leftward or anticlockwise rotation. SYN: levogyrate, levogyrous.

levorphanol tartrate
levorphanol tartrate (lev-orf′a-nol)

An analgesic similar in action to morphine.

levotorsion
levotorsion (le-vo-tor′shun)

1. SYN: sinistrotorsion. 2. Rotation of the upper pole of the cornea of one or both eyes to the left. SYN: levoclination. [levo- + L. torsio, a twisting]

levoversion
levoversion (le′vo-ver′zhun)

1. Version toward the left. 2. Conjugate turning of both eyes to the left. [levo- + L. verto, pp. versus, to turn]

Levret
Levret

André, French obstetrician, 1703–1780. See L. forceps, Mauriceau-L. maneuver.

levulan
levulan (lev′u-lan)

SYN: fructosan (1) .

levulic acid
levulic acid (lev′u-lik)

SYN: levulinic acid.

levulin
levulin (lev′u-lin)

SYN: fructosan (1) .

levulinate
levulinate (lev′u-lin-at)

A salt or ester of levulinic acid.

levulinic acid
levulinic acid (lev-u-lin′ik)

4-Oxopentanoic acid;formed by the action of hot, strong acids on hexoses. SEE ALSO: δ-aminolevulinic acid. SYN: levulic acid.

levulosan
levulosan (lev′u-lo-san)

SYN: fructosan (1) .

levulose
levulose (lev′u-los)

d-Fructose. See fructose.

levulosemia
levulosemia (lev′u-lo-se′me-a)

SYN: fructosemia.

levulosuria
levulosuria (lev′u-lo-soo′re-a)

SYN: fructosuria.

Lévy
Lévy

Gabrielle, French neurologist, 1886–1935. See Roussy-L. disease, Roussy-L. syndrome.

Lewandowski
Lewandowski

Felix, German dermatologist, 1879–1921. See Jadassohn-L. syndrome.

Lewis
Lewis

Gilbert N., U.S. chemist, 1875–1946. SEE ALSO: L. acid, L. base, second law of thermodynamics.

Lewis
Lewis

Ivor, Welsh surgeon who in 1946 reported to the Royal College of Surgeons a two-stage esophagectomy by laparotomy and right thoracotomy, performed today as one procedure. See Ivor L. esophagectomy.

Lewis Blood Group
Lewis Blood Group, Le Blood Group

See Blood Groups Appendix.

lewisite
lewisite (loo′i-sit)

A war gas. It is a vesicant, a lung irritant like mustard gas, a systemic poison entering the circulation through the lungs or skin, and a mitotic poison arresting mitosis in the metaphase; dimercaprol is the antidote. SYN: β-chlorovinyldichloroarsine. [W. Lee Lewis, U.S. chemist, 1898–1943]

Lewy
Lewy, Lewey

Frederic H., German neurologist in the U.S., 1885–1950. See L. bodies, under body, L. body dementia, diffuse L. body disease.

lexical
lexical (leks′i-kal)

Denoting the vocabulary of speech or language.

-lexis -lexis, -lexy

Suffixes that properly relate to speech, although often confused with -legia (L. lego, to read) and thus erroneously employed to relate to reading. [G. lexis, word, speech, from lego, to say]

Leyden
Leyden

Ernst V. von, German physician, 1832–1910. See L. ataxia, L. crystals, under crystal, L. neuritis, L.-Möbius muscular dystrophy.

Leydig
Leydig

Franz von, German anatomist, 1821–1908. See L. cells, under cell, L. cell tumor, Sertoli-L. cell tumor.

leydigarche
leydigarche (li′dig-ar-ke)

Obsolete term for the beginning of gonadal function in the male, e.g., male puberty. [Leydig (see Leydig cells), + G. arche, beginning]

Lf
Lf, L_f

See dose.

LFA
LFA

Abbreviation for left frontoanterior position; lymphocyte function associated antigen.

LFP
LFP

Abbreviation for left frontoposterior position.

LFT
LFT

Abbreviation for left frontotransverse position.

LGSIL
LGSIL

Abbreviation for low-grade squamous intraepithelial lesion.

LH
LH

Abbreviation for luteinizing hormone.

Lhermitte
Lhermitte

Jean, French neurologist, 1877–1959. See L. sign.

LH/FSH-RF
LH/FSH-RF

Abbreviation for luteinizing hormone/follicle-stimulating hormone-releasing factor.

LH-RF
LH-RF

Abbreviation for luteinizing hormone-releasing factor.

LH-RH
LH-RH

Abbreviation for luteinizing hormone-releasing hormone.

Li
Li

Frederick P., 20th century epidemiologist. See L.-Fraumeni cancer syndrome.

Li
Li

Symbol for lithium.

liberator
liberator (lib′er-a-ter, -tor)

An agent that stimulates or activates a physiological chemical or an enzymatic action.
histamine liberators substances that cause the release of histamine from mast cells or basophils.

liberins
liberins (lib′er-ins)

SYN: releasing factors. [L. libero, to free, + -in]

liberomotor
liberomotor (lib′er-o-mo′ter)

Relating to voluntary movements. [L. liber, free, + motor, mover]

libidinization
libidinization (li-bid′i-ni-za′shun)

SYN: erotization.

libidinous
libidinous (li-bid′i-nus)

Lascivious; invested with or arousing sexual desire or energy. [L. libidinosus, fr. libido (libidin-), pleasure, desire]

libido
libido (li-be′do, -bi′do)

1. Conscious or unconscious sexual desire. 2. Any passionate interest or form of life force. 3. In jungian psychology, synonymous with psychic energy. [L. lust]
object l. l. invested in the object, in contradistinction to that invested in the ego.

Libman
Libman

Emanuel, U.S. physician, 1872–1946. See L.-Sacks endocarditis, L.-Sacks syndrome.

Liborius
Liborius

Paul, 19th century Russian bacteriologist. See L. method.

library
library (li′brar-e)

A collection of cloned fragments that represent the entire genome.
cDNA l. a collection of copy (cDNA) fragments that have been made by reverse transcriptase from the mRNA of a particular cell, organ, or organism.
genomic l. l. in which both introns and exons are represented; a l. prepared from genomic DNA.
l. screening the process of selection of a desired clone from the collection.

lice
lice (lis)

Plural of louse.

lichen
lichen (li′ken)

A discrete flat papule or an aggregate of papules giving a patterned configuration resembling l. growing on rocks. [G. leichen, l.; a lichenlike eruption]
l. myxedematosus a lichenoid eruption of papules on the upper body of mucinous edema due to deposit of glycosaminoglycans in the skin and fibroblast proliferation, in the absence of endocrine disease. Monoclonal gammopathy is often present. SEE ALSO: scleromyxedema. SYN: papular mucinosis.
l. nitidus minute asymptomatic whitish or pinkish papules; lesions, which are flat-topped, rarely may coexist with l. planus and may involve male genitalia.
l. nuchae l. simplex of the neck, usually in women.
l. obtusus a form in which the papules are large and rounded instead of flattened.
oral (erosive) l. planus oral manifestations of l. planus characterized by white striae (Wickham striae) of the oral mucous membrane and sometimes associated with ulceration; patients may or may not exhibit a history of cutaneous l. planus.
l. planopilaris a rare, patchy alopecia with follicular hyperkeratosis of the scalp and lymphocytic perifolliculitis with l. planus elsewhere.
l. planus eruption of flat-topped, shiny, violaceous papules on flexor surfaces, male genitalia, and buccal mucosa of unknown cause; may form linear groups; microscopically characterized by a band-like subepidermal lymphocytic infiltrate. Spontaneous resolution is common after months to years.
l. planus annularis a form in which the papules are grouped in ring figures.
l. planus follicularis l. planus of the hair follicles, usually of the scalp.
l. planus hypertrophicus verrucoid or warty lesions occurring on legs and thighs in association with l. planus elsewhere. SYN: l. planus verrucosus.
l. planus verrucosus SYN: l. planus hypertrophicus.
l. ruber moniliformis a rare dermatosis consisting of small reddish papules arranged in narrow beaded bands and covering large areas of the body.
l. sclerosus et atrophicus an eruption consisting of pruritic white atrophic papules and plaques that may be discrete or confluent and may contain a central depression or a black keratotic plug microscopically showing epidermal hyperkeratosis and atrophy, superficial dermal edema and homogenization, and mid-dermal inflammation; occurs most commonly in prepubertal and postmenopausal females; vulval involvement was formerly called kraurosis vulvae.
l. scrofulosorum small asymptomatic l. papules on the trunk of children with tuberculosis; acid-fast bacilli are not seen in the dermal granulomas. SYN: papular tuberculid.
l. simplex chronicus a thickened area of itching skin resulting from rubbing and scratching.
l. spinulosus eruption of conical papules, of unknown cause, which have an adherent scaly surface; may be related to l. planus.
l. striatus a self-limited papular eruption occurring primarily in children (more commonly in females); the lesions are arranged in linear groups and usually occur on one extremity.

lichenification
lichenification (li′ken-i-fi-ka′shun)

Leathery induration and thickening of the skin with hyperkeratosis, caused by scratching, as in atopic or chronic contact dermatitis. [lichen + L. facio, to make]

lichenin
lichenin (li′ken-in)

A variety of polysaccharide obtained from Iceland moss; used as a demulcent. SYN: moss starch.

lichenoid
lichenoid (li′ke-noyd)

1. Resembling lichen. 2. Accentuation of normal skin markings observed in cases of chronic eczema. 3. Microscopically resembling lichen planus.

Lichtenstein
Lichtenstein

Louis, U.S. physician, 1906–1977. See Jaffe-L. disease.

licorice
licorice (lik′o-ris)

SYN: glycyrrhiza.

lid
lid

SYN: eyelid. [A.S. hlid]
granular lids SYN: trachoma.
lower l. SYN: inferior eyelid.
upper l. SYN: superior eyelid.

Liddell
Liddell

Edward G.T., English neurophysiologist, 1895–1981. See L.-Sherrington reflex.

lidocaine hydrochloride
lidocaine hydrochloride (li′do-kan)

A local anesthetic with antiarrhythmic and anticonvulsant properties.

lidoflazine
lidoflazine (li-do-fla′zen)

A coronary vasodilator.

lie
lie (li)

Relationship of the long axis of the fetus to that of the mother.
longitudinal l. that relationship in which the long axis of the fetus is longitudinal and roughly parallel to the long axis of the mother; the presenting part may be either the head or the breech.
oblique l. that relationship in which the long axis of the fetus crosses the maternal axis at an angle other than a right angle.
transverse l. that relationship in which the long axis of the fetus is transverse or at right angles to that of the mother.
unstable l. oblique orientation of the fetus that is neither transverse nor longitudinal, but that converts to one or the other before or during labor.

Lieberkühn
Lieberkühn

Johann N., German anatomist, 1711–1756. See crypts of L., under crypt, L. follicles, under follicle, L. glands, under gland.

lieberkühn
lieberkühn (le′ber-koon)

A concave reflector around the objective of a microscope, for the purpose of directing a concentrated beam of light on the material being examined. [J.N. L.]

Liebermann
Liebermann

Leo von S., Hungarian physician, 1852–1926. See Burchard-L. reaction, L.-Burchard test.

Liebermeister
Liebermeister

Carl von, German physician, 1833–1901. See L. rule.

Liebig
Liebig

Baron Justus von, German chemist, 1803–1873. See L. theory.

Liebow
Liebow (le′-bo)

Averill A., Austrian-U.S. pulmonary pathologist, 1911–1978. See usual interstitial pneumonia of L..

lie detector
lie detector

SYN: polygraph (2) .

lien
lien (li′en)

spleen. [L.]
l. accessorius accessory spleen.
l. mobilis SYN: floating spleen.
l. succenturiatus SYN: accessory spleen.

lien- lien-, lieno-

The spleen; most terms beginning thus are obsolete or obsolescent. See spleno-. [L. lien]

lienal
lienal (li′e-nal)

SYN: splenic.

lienculus
lienculus (li-en′ku-lus)

SYN: accessory spleen. [Mod. L. dim. of L. lien, spleen]

lienectomy
lienectomy (li′e-nek′to-me)

Obsolete term for splenectomy.

lienomedullary
lienomedullary (li′e-no-med′u-lar-e)

SYN: splenomyelogenous. [lieno- + G. medulla, marrow]

lienomyelogenous
lienomyelogenous (li′e-no-mi-e-loj′e-nus)

SYN: splenomyelogenous.

lienopancreatic
lienopancreatic (li′e-no-pan′kre-at′ik)

SYN: splenopancreatic.

lienorenal
lienorenal (li′e-no-re′nal)

SYN: splenorenal. [lieno- + L. ren, kidney]

lienteric
lienteric (li-en-ter′ik)

Relating to, or marked by, lientery.

lientery
lientery (li′en-ter-e)

Passage of undigested food in the stools. [G. leienteria, fr. leios, smooth, + enteron, intestine]

lienunculus
lienunculus (li′e-nun′ku-lus)

SYN: accessory spleen. [Mod. L. dim. of L. lien, spleen]

Liesegang
Liesegang

Ralph E., German chemist, 1869–1947. See L. rings, under ring.

Lieutaud
Lieutaud

Joseph, French anatomist and pathologist, 1703–1780. See L. body, L. triangle, L. trigone, L. uvula.

life
life (lif)

1. Vitality, the essential condition of being alive; the state of existence characterized by such functions as metabolism, growth, reproduction, adaptation, and response to stimuli. 2. Living organisms such as animals and plants. [A.S. lif]
half-l. half-l..
postnatal l. that interval of l. after birth; in humans, usually divided into periods: neonatal, infancy, childhood, adolescence, and adulthood.
prenatal l. that interval of l. between conception and birth; in humans, usually divided into embryonic and fetal periods.
quality of l. a patient's general well-being, including mental status, stress level, sexual function, and self-perceived health status.
sexual l. in psychiatry and psychoanalysis, the specifically erotic or sexual interests, fantasies, inclinations, and conduct of the patient.
vegetative l. the simple metabolic and reproductive activity of humans or animals, apart from the exercise of conscious mental or psychic processes.

life events
life events

Occurrences in one's daily life, some of which act as stressors.

lifespan
lifespan

1. The duration of life of an individual. 2. The normal or average duration of life of members of a given species. SEE ALSO: longevity.

life-style
life-style

The set of habits and customs that is influenced by the lifelong process of socialization, including social use of substances such as alcohol and tobacco, dietary habits, exercise, etc., all of which have important implications for health.

ligament
ligament (lig′a-ment) [TA]

1. A band or sheet of fibrous tissue connecting two or more bones, cartilages, or other structures, or serving as support for fasciae or muscles. 2. A fold of peritoneum supporting any of the abdominal viscera. 3. Any structure resembling a l. though not performing the function of such. 4. The cordlike remains of a fetal vessel or other structure that has lost its original lumen. SYN: ligamentum [TA] . [L. ligamentum, a band, bandage]
accessory ligaments ligaments about a joint that are in addition to the articular capsule. They may lie within (intracapsular ligaments) or on the outside (extracapsular ligaments) of the articular capsule.
accessory plantar ligaments SYN: plantar ligaments.
accessory volar ligaments SYN: palmar ligaments.
acromioclavicular l. [TA] a fibrous band extending from the acromion of the scapula to the clavicle. SYN: ligamentum acromioclaviculare [TA] .
alar ligaments one of a pair of short stout bands that extends from the side of the dens of the axis to the tubercle on the medial aspect of the occipital condyle; SYN: check ligaments of odontoid.
alveolodental l. SYN: periodontium.
anococcygeal l. a musculofibrous band that passes between the anus and the coccyx. SYN: anococcygeal body, ligamentum anococcygeum, raphe anococcygea, Symington anococcygeal body.
anterior costotransverse l. SYN: superior costotransverse l..
anterior cruciate l. [TA] the l. that extends from the anterior intercondylar area of the tibia to the posterior part of the medial surface of the lateral condyle of the femur. SYN: ligamentum cruciatum anterius.
anterior l. of fibular head [TA] a l. uniting the anterior part of the head of the fibula to the tibia. SYN: ligamentum capitis fibulae anterius [TA] .
anterior l. of Helmholtz anterior l. of malleus.
anterior longitudinal l. [TA] the wide fibrous band interconnecting the anterolateral surfaces of the vertebral bodies, blending with the outer lamellae of the intervertebral disks as it passes between vertebrae. SYN: ligamentum longitudinale anterius [TA] , lacertus medius.
anterior l. of malleus [TA] consists of two portions: Meckel band, passing from the base of the anterior process to the spine of the sphenoid through the petrotympanic fissure; and the anterior l. of Helmholtz, extending from the anterior aspect of the neck of the malleus to the anterior boundary of the tympanic notch. SYN: ligamentum mallei anterius [TA] .
anterior meniscofemoral l. [TA] the ligamentous band that passes anterior to the posterior cruciate l., extending between the posterior portion of the lateral meniscus and the upper end of the anterior cruciate l.. SYN: ligamentum meniscofemorale anterius [TA] , Humphry l..
anterior sacrococcygeal l. [TA] the continuation of the anterior longitudinal l. uniting the sacrum and coccyx. SYN: ligamentum sacrococcygeum anterius [TA] , ventral sacrococcygeal l..
anterior sacroiliac ligaments [TA] the strong fibrous bands that reinforce the sacroiliac joint anteriorly. SYN: ligamenta sacroiliaca anteriora [TA] , ventral sacroiliac ligaments.
anterior sacrosciatic l. SYN: sacrospinous l..
anterior sternoclavicular l. [TA] a fibrous band that reinforces the sternoclavicular anteriorly. SYN: ligamentum sternoclaviculare anterius [TA] .
anterior talofibular l. [TA] the band of fibers that extends from the lateral malleolus to the neck of the talus. SYN: ligamentum talofibulare anterius [TA] .
anterior talotibial l. SYN: anterior tibiotalar part of medial l. of ankle joint. SEE ALSO: medial l. of ankle joint.
anterior tibiofibular l. [TA] the l. that binds the anterior aspect of the tibiofibular syndesmosis. SYN: ligamentum tibiofibulare anterius [TA] .
anterior tibiotalar l. SYN: anterior tibiotalar part of medial l. of ankle joint.
anular l. [TA] one of a number of ligaments encircling various parts; the principal anular ligaments are those of the stapes, radius, and trachea. See anular l. of radius, anular l. of stapes, anular ligaments of trachea. SYN: ligamentum anulare [TA] , orbicular l..
anular l. of radius [TA] the l. that encircles and holds the head of the radius in the radial notch of the ulna, forming the proximal radioulnar joint and enabling pronation/supination of forearm; receives the radial collateral l. of the elbow. SYN: ligamentum anulare radii [TA] , ligamentum orbiculare radii, orbicular l. of radius.
anular l. of stapes [TA] a ring of elastic fibers that attaches the base of the stapes to the margin of the fenestra vestibuli. SYN: ligamentum anulare stapedis [TA] .
anular ligaments of trachea [TA] the fibrous membranes that connect adjacent tracheal cartilages. SYN: ligamenta anularia trachealia [TA] , ligamenta trachealia.
apical l. of dens [TA] a l. that extends from the apex of the dens of the axis to the anterior margin of the foramen magnum; includes vestiges of notochord. SYN: ligamentum apicis dentis.
Arantius l. SYN: ligamentum venosum.
arcuate popliteal l. [TA] a broad fibrous band attached above to the lateral condyle of the femur and passing medially and downward, blending with the posterior part of the fibrous capsule of the knee joint, arching over the tendon of the popliteus muscle. SYN: ligamentum popliteum arcuatum [TA] , popliteal arch, posterior l. of knee.
arcuate pubic l. SYN: inferior pubic l..
arterial l. SYN: ligamentum arteriosum.
ligaments of auditory ossicles [TA] the ligaments connecting the ear bones with one another and with the walls of the tympanic cavity. SYN: ligamenta ossiculorum auditus [TA] , ligamenta ossiculorum auditorium&star.
ligaments of auricle [TA] the three ligaments that attach the auricle to the side of the head: anterior l. of auricle (ligamentum auriculare anterius), which extends from the root of the zygomatic process to the spine of the helix; posterior l. of auricle (ligamentum auriculare posterius), which extends from the mastoid process to the conchal eminence; superior l. of auricle (ligamentum auriculare superius), which extends from the superior margin of the osseous external acoustic meatus to the spine of the helix. SYN: ligamenta auricularia [TA] , auricular ligaments, Valsalva ligaments.
auricular ligaments SYN: ligaments of auricle.
axis l. of malleus SYN: Helmholtz axis l..
Bardinet l. the posterior band of the ulnar collateral l. of the elbow.
Barkow ligaments the anterior and posterior portions of the fibrous capsule of the elbow joint.
Bellini l. a fasciculus from the ischiofemoral portion of greater articular fibrous capsule of the hip that extends to the greater trochanter.
Berry ligaments SYN: lateral thyrohyoid l..
Bertin l. SYN: iliofemoral l..
Bichat l. the lower fasciculus of the posterior sacroiliac l..
bifurcate l. [TA] a strong, V-shaped dorsal tarsal l. on the dorsum of the foot that passes from the calcaneus distal to the tarsal sinus and attaches to cuboid and navicular bones; it is divided into the calcaneocuboid l. and the calcaneonavicular l.. SYN: ligamentum bifurcatum [TA] , bifurcated l..
bifurcated l. SYN: bifurcate l..
Bigelow l. SYN: iliofemoral l..
Botallo l. SYN: ligamentum arteriosum.
Bourgery l. SYN: oblique popliteal l..
broad l. of the uterus [TA] the peritoneal fold passing from the lateral margin of the uterus to the wall of the pelvis on either side, and in so doing also ensheathing the ovaries and uterine tubes. SYN: ligamentum latum uteri [TA] .
Brodie l. SYN: transverse humeral l..
Burns l. SYN: superior horn of falciform margin of saphenous opening.
calcaneocuboid l. [TA] the lateral part of the bifurcate ligamentum. SYN: ligamentum calcaneocuboideum [TA] .
calcaneofibular l. [TA] the middle of the three fascicles that form the lateral l. of the ankle joint, reinforcing the lateral side of the ankle joint and resisting excessive inversion of the foot; the remaining two ligaments of the lateral ligaments are the anterior and posterior talofibular ligaments. SYN: ligamentum calcaneofibulare [TA] .
calcaneonavicular l. [TA] the medial part of the bifurcate l.. SYN: ligamentum calcaneonaviculare [TA] .
calcaneotibial l. SYN: tibiocalcaneal part of medial l. of ankle joint. SEE ALSO: medial l. of ankle joint.
Caldani l. SYN: coracoclavicular l..
Campbell l. SYN: suspensory l. of axilla.
Camper l. SYN: perineal membrane.
capsular l. [TA] thickened portions of the fibrous membrane of an articular capsule. SYN: ligamentum capsulare [TA] .
cardinal l. [TA] a fibrous band attached to the uterine cervix and the vault of the lateral fornix of the vagina; continuous with the tissue ensheathing the pelvic vessels. SYN: ligamentum cardinale [TA] , transverse cervical l.&star, cervical l. of uterus, ligamentum transversale cervicis, Mackenrodt l..
caroticoclinoid l. the l. that connects the anterior to the middle clinoid process of the sphenoid bone.
carpometacarpal ligaments (dorsal and palmar) [TA] the ligaments uniting the metacarpal and carpal bones. SYN: ligamenta carpometacarpalia (dorsalia/palmaria) [TA] .
caudal l. SYN: retinaculum caudale.
ceratocricoid l. [TA] one of three ligaments (anterior, posterior, and lateral) reinforcing the capsule of the cricothyroid articulation on either side. SYN: ligamentum ceratocricoideum [TA] .
cervical l. of uterus SYN: cardinal l..
check ligaments of eyeball, medial and lateral SYN: check ligaments of medial and lateral rectus muscles.
check ligaments of medial and lateral rectus muscles [TA] expansions of the sheaths of the medial and lateral rectus muscles of the eyeball that are attached, respectively, to the lacrimal bone and to the orbital tubercle of the zygomatic bone; they serve to prevent overaction of these muscles. Terminologia Anatomica recognizes only the check ligametn of lateral rectus muscle. SYN: check ligaments of eyeball, medial and lateral.
check ligaments of odontoid SYN: alar ligaments.
chondroxiphoid l. SYN: costoxiphoid l..
ciliary l. SYN: ciliary muscle.
Civinini l. SYN: pterygospinous l..
Clado l. a mesenteric fold running from the broad l. on the right side to the appendix.
coccygeal l. dural part of filum terminale.
collateral l. [TA] one of a number of ligaments on either side of, and serving as a radius of movement of, a joint having a hingelike movement; they occur at the following joints: elbow, knee, wrist, and the metacarpo- or metatarsophalangeal, proximal interphalangeal, and distal interphalangeal joints of the hands and feet. SYN: ligamentum collaterale [TA] .
Colles l. SYN: reflected inguinal l..
conoid l. [TA] the medial part of the coracoclavicular l. that attaches to the conoid tubercle of the clavicle. The conoid l. and its partner coracoclavicular l., the trapezoid l., passively suspend the free upper limb from the strut formed by the clavicle. SYN: ligamentum conoideum [TA] .
Cooper ligaments 1. SYN: suspensory ligaments of breast. 2. SYN: pectineal l.. 3. SYN: transverse l. of elbow.
coracoacromial l. [TA] the heavy arched fibrous band that passes between the coracoid process and the acromion above the shoulder joint; the osseofibrous arch thus formed prevents upward dislocation of the shoulder (glenohumeral) joint. SYN: ligamentum coracoacromiale [TA] .
coracoclavicular l. [TA] the strong compound l. that unites the clavicle to the coracoid process; it is subdivided into the conoid ligamentum and the trapezoid ligamentum. The free upper limb is passively suspended from the clavicular “strut” by the coracoclavicular l.; the l. also plays an important role in preventing dislocation of the acromioclavicular joint. SYN: ligamentum coracoclaviculare [TA] , Caldani l..
coracohumeral l. [TA] the l. that passes from the base of the coracoid process to the greater tubercle of the humerus. SYN: ligamentum coracohumerale [TA] .
corniculopharyngeal l. SYN: cricopharyngeal l..
coronary l. of knee portions of the articular capsule of the knee joint that connect the circumference of the menisci with the margins of the condyles of the tibia.
coronary l. of liver [TA] peritoneal reflections from the liver to the diaphragm at the margins of the bare area of the liver. SYN: ligamentum coronarium hepatis [TA] .
costoclavicular l. [TA] the l. that connects the first rib and the clavicle near its sternal end; limits elavation of shoulder (at sternoclavicular joint). SYN: ligamentum costoclaviculare [TA] , rhomboid l..
costocolic l. SYN: phrenicocolic l..
costotransverse l. [TA] the l. that connects the dorsal aspect of the neck of a rib to the ventral aspect of the corresponding transverse process. SEE ALSO: lateral costotransverse l., superior costotransverse l.. SYN: ligamentum costotransversarium [TA] , ligamentum colli costae, middle costotransverse l..
costoxiphoid l. [TA] the l. that connects the xiphoid process to the seventh, and often to the sixth, costal cartilages. SYN: ligamentum costoxiphoideum [TA] , chondroxiphoid l..
cotyloid l. SYN: acetabular labrum.
Cowper l. the part of the fascia lata which is anterior to and provides origin for fibers of the pectineus muscle.
cricoarytenoid l. [TA] the l. that passes downward from the posterior border of the arytenoid cartilage to the lamina of the cricoid cartilage. SYN: ligamentum cricoarytenoideum posterius, posterior cricoarytenoid l..
cricopharyngeal l. [TA] an elastic band connecting the tip of the corniculate (Santorini) cartilage and the lamina of the cricoid cartilage and continuing into the pharyngeal mucosa covering the cricoid lamina. SYN: ligamentum cricopharyngeum [TA] , corniculopharyngeal l., cricosantorinian l., jugal l., ligamentum corniculopharyngeum, ligamentum jugale.
cricosantorinian l. SYN: cricopharyngeal l..
cricotracheal l. [TA] a midline fibrous band connecting the cricoid cartilage with the first ring of the trachea. SYN: ligamentum cricotracheale [TA] , cricotracheal membrane.
crucial l. 1. See inferior extensor retinaculum, superior extensor retinaculum. 2. SYN: cruciate ligaments of knee. 3. SYN: cruciate l. of the atlas. 4. SYN: cruciform part of fibrous digital sheath.
cruciate l. of the atlas [TA] the strong l. that lies posterior to the dens of the axis holding it against the anterior arch of the atlas; it consists primarily of the transverse l. of the atlas that forms the cross-bar of the cross and is most important functionally, and longitudinal bands of the cruciform l., forming the upright or vertical beams of the cross. SYN: ligamentum cruciforme atlantis [TA] , crucial l. (3) , cruciform l. of atlas, ligamentum cruciatum atlantis.
cruciate ligaments of knee the two ligaments that pass from the intercondylar area of the tibia to the intercondylar fossa of the femur. See anterior cruciate l., posterior cruciate l.. SEE ALSO: anterior cruciate l., posterior cruciate l.. SYN: crucial l. (2) , ligamenta cruciata genus.
cruciate l. of leg SYN: inferior extensor retinaculum.
cruciform l. of atlas SYN: cruciate l. of the atlas.
Cruveilhier ligaments SYN: plantar ligaments.
cuboideonavicular ligaments [TA] l. uniting the cuboid bone with the navicular bone. See dorsal cuboideonavicular l., plantar cuboideonavicular ligaments. SYN: ligamenta cuboideonaviculare [TA] .
cuneocuboid ligaments [TA] l. uniting the lateral cuneiform bone with the cuboid bone. See dorsal cuneocuboid l., cuneocuboid interosseous l., plantar cuneocuboid l.. SYN: ligamentum cuneocuboideum [TA] .
cuneocuboid interosseous l. [TA] the fibrous band that unites adjacent margins of the distal end of the lateral cuneiform and cuboid bones. SYN: interosseous cuneocuboid l., ligamentum cuneocuboideum interosseum.
cuneometatarsal interosseous ligaments [TA] ligaments that pass from the cuneiform bones to the metatarsals, the one from the first cuneiform to the second metatarsal being the strongest. SYN: ligamenta cuneometatarsalia interossea [TA] , interosseous cuneometatarsal ligaments, Lisfranc ligaments.
cuneonavicular ligaments ligaments uniting the medial cuneiform bone with the navicular. SEE ALSO: dorsal cuneonavicular ligaments, plantar cuneonavicular ligaments.
cystoduodenal l. a peritoneal fold that sometimes passes from the gallbladder to the first part of the duodenum.
deep dorsal sacrococcygeal l. SYN: deep posterior sacrococcygeal l..
deep posterior sacrococcygeal l. the continuation of the posterior longitudinal l. uniting the sacrum and coccyx. SYN: deep dorsal sacrococcygeal l., ligamentum sacrococcygeum posterius profundum.
deep transverse metacarpal l. [TA] the l. that interconnects the palmar surface of the heads of the second to fifth metacarpals, being continuous with the palmar ligaments or palmar plates; it lies in the plane of the palmar interosseous fascia. SYN: ligamentum metacarpale transversum profundum [TA] , transverse metacarpal l..
deep transverse metatarsal l. [TA] the l. that interconnects the plantar surface of the heads of the metatarsals, being continuous with the plantar ligaments. SYN: ligamentum metatarsale transversum profundum [TA] , transverse metatarsal l..
deltoid l. medial l. of ankle joint.
Denonvilliers l. SYN: puboprostatic l..
dentate l. of spinal cord rarely used variation on the spelling of denticulate l..
denticulate l. [TA] a serrated, shelflike extension of the spinal pia mater projecting in a frontal plane from either side of the cervical and thoracic spinal cord; its approximately 21 pointed processes fuse laterally with the arachnoid and dura mater midway between the exits of the roots of adjacent spinal nerves, with the highest process attaching immediately superior to foramen magnum. SYN: ligamentum denticulatum [TA] .
Denucé l. SYN: quadrate l..
diaphragmatic l. of the mesonephros the segment of the urogenital ridge that extends from the mesonephros to the diaphragm; becomes the suspensory l. of the ovary. SYN: urogenital mesentery.
dorsal calcaneocuboid l. See bifurcate l..
dorsal carpal l. SYN: extensor retinaculum.
dorsal carpometacarpal ligaments [TA] fibrous bands that connect the dorsal surfaces of the carpal and metacarpal bones. SYN: ligamenta carpometacarpalia dorsalia [TA] .
dorsal cuboideonavicular l. [TA] the dorsal tarsal l. that unites the dorsal surfaces of the cuboid and navicular bones of the tarsus. SYN: ligamentum cuboideonaviculare dorsale [TA] .
dorsal cuneocuboid l. [TA] one of the dorsal tarsal ligaments appearing as a fibrous band that unites the dorsal margins of the lateral cuneiform and cuboid bones. SYN: ligamentum cuneocuboideum dorsale [TA] .
dorsal cuneonavicular ligaments [TA] several ligaments connecting the dorsal surface of the navicular with the three cuneiform bones. SYN: ligamenta cuneonavicularia dorsalia [TA] .
dorsal intercuneiform ligaments [TA] the dorsal tarsal l. extending between adjacent cuneiform bones.
dorsal metacarpal ligaments [TA] fibrous bands connecting the dorsal aspects of the bases of metacarpals two to five. SYN: ligamenta metacarpalia dorsalia [TA] .
dorsal metatarsal ligaments [TA] fibrous bands that connect the dorsal aspects of the bases of the metatarsals. SYN: ligamenta metatarsalia dorsalia [TA] .
dorsal radiocarpal l. [TA] the l. that extends from the distal end of the radius posteriorly to the proximal row of carpal bones. SYN: ligamentum radiocarpale dorsale [TA] .
dorsal sacroiliac ligaments SYN: posterior sacroiliac ligaments.
dorsal tarsal ligaments [TA] ligaments connecting dorsal aspects of the tarsal bones as a group; included in the group are the: talonavicular l. [TA] (ligamentum talonaviculare [TA]), bifurcate l. [TA] (ligamentum bifurcatum [TA]), and the following dorsal ligaments (ligamentum/a . . . dorsalia/e): intercuneiform [TA] (intercuneiformia [TA]), cuneocuboid [TA] (cuneocuboideum [TA]), cuboideonavicular [TA] (cuboideonaviculare [TA]), cuneonavicular [TA] (cuneonavicularia [TA]), and calcaneocuboid [TA] (calcaneocuboideum [TA]). SYN: ligamenta tarsi dorsalia [TA] .
dorsal tarsometatarsal ligaments [TA] strong, flat, longitudinal, and oblique bands reinforcing the dorsal aspects of the tarsometatarsal joints (joints between the metatarsals and the cuboid and cuneiform bones); the first metatarsal and medial cuneiform share an exclusive joint capsule, and the medial dorsal tarsometatarsal ligaments connect only those bones; the remaining metatarsals have attachments to multiple bones, with the ligaments reinforcing the dorsal aspect of their common joint capsule. SYN: ligamenta tarsometatarsalia dorsalia [TA] .
duodenorenal l. a fold of peritoneum occasionally passing from the termination of the hepatoduodenal l. to the front of the right kidney. SYN: ligamentum duodenorenale.
ligaments of epididymis (inferior and superior) one of two folds (superior and inferior) of the tunica vaginalis between the epididymis and the testis. SYN: ligamenta epididymidis (inferius et superius) [TA] .
epihyal l. SYN: stylohyoid l..
external collateral l. of wrist SYN: radial collateral l. of wrist joint.
extracapsular ligaments [TA] ligaments associated with a synovial joint but separate from and external to its articular capsule. SYN: ligamenta extracapsularia [TA] .
falciform l. SYN: falciform process of sacrotuberous l..
falciform l. of liver [TA] a crescentic fold of peritoneum extending to the surface of the liver from the diaphragm and anterior abdominal wall; the round l. lies in its free inferior border, derivative of embryonic ventral mesogastrium. SYN: ligamentum falciforme hepatis [TA] .
fallopian l. SYN: inguinal l..
Ferrein l. SYN: lateral l. of temporomandibular joint.
fibular collateral l. [TA] the cordlike l. that passes from the lateral epicondyle of the femur to the head of the fibula. SYN: ligamentum collaterale fibulare [TA] , lateral l. of knee, Winslow l..
fibular collateral l. of ankle SYN: lateral l. of ankle.
Flood l. a band of the coracohumeral l., attached to the lower part of the lesser tuberosity of the humerus.
fundiform l. of clitoris [TA] fibrous condensation of the subcutaneous tissue descending from the linea alba above the pubic symphysis to split and surround the root of the body of the clitoris, before fusing with the fascia of the clitoris. SYN: ligamentum fundiforme clitoridis [TA] .
fundiform l. of foot SYN: Retzius l..
fundiform l. of penis [TA] a band of elastic fibers of the superficial fascial layer that extends from the linea alba above the pubic symphysis splitting to surround the penis before attaching to the fascia of the penis. SYN: ligamentum fundiforme penis [TA] .
gastrocolic l. [TA] the major, apron-like portion of the greater omentum that extends between the stomach and the transverse colon. SYN: ligamentum gastrocolicum [TA] .
gastrodiaphragmatic l. SYN: gastrophrenic l..
gastrolienal l. SYN: gastrosplenic l..
gastrophrenic l. [TA] the portion of the greater omentum that extends from the greater curvature of the stomach to the inferior surface of the diaphragm. SYN: ligamentum gastrophrenicum [TA] , gastrodiaphragmatic l., phrenogastric l..
gastrosplenic l. [TA] the portion of the greater omentum that lies between the greater curvature of the stomach and the hilum of the spleen. SYN: ligamentum gastrosplenicum [TA] , ligamentum gastrolienale&star, gastrolienal l., gastrosplenic omentum.
genital l. an embryonic mesenchymatous band providing support for the internal genitalia. SYN: suspensory l. of gonad.
genitoinguinal l. in the fetus, a fold of the mesorchium containing the gubernaculum testis. SYN: ligamentum genitoinguinale, plica gubernatrix.
Gerdy l. SYN: suspensory l. of axilla.
Gillette suspensory l. SYN: cricoesophageal tendon.
Gimbernat l. SYN: lacunar l..
gingivodental l. SYN: periodontium.
glenohumeral ligaments [TA] three fibrous bands (capsular ligaments) that reinforce the anterior part of the articular capsule of the shoulder joint; they are in continuity with the glenoid labrum at the supraglenoid tubercle of the scapula and blend with the fibrous capsule as it attaches to the anatomic neck of the humerus; they are conspicuous as folds or ridges on the internal aspect of the articular capsule. SYN: ligamenta glenohumeralia [TA] .
glenoid l. 1. SYN: glenoid labrum of scapula. 2. SYN: plantar ligaments.
glossoepiglottic l. an elastic ligamentous band passing from the base of the tongue to the epiglottis in the middle glossoepiglottic fold.
Günz l. a portion of the superficial layer of the obturator membrane.
hammock l. the part of the periodontium below the growing end of the root of the tooth.
l. of head of femur [TA] a flattened l. that passes from the fovea in the head of the femur to the borders of the acetabular notch (transverse acetabular l.); developmentally, an artery passes to the head of the femur with the l. which may or may not persist into adulthood; the l. does not contribute to the integrity of the joint or control movements there. SYN: ligamentum capitis femoris [TA] , ligamentum teres femoris, round l. of femur.
Helmholtz axis l. a l. forming the axis about which the malleus rotates; it consists of two portions extending from the anterior and the posterior border, respectively, of the tympanic notch to the malleus. SYN: axis l. of malleus.
Hensing l. the left superior colic l.; a small serous horizontal or oblique fold sometimes found extending between the upper end of the descending colon and the abdominal wall. See phrenicocolic l..
hepatocolic l. [TA] an inconstant extension of the hepatoduodenal l. to the transverse colon. SYN: ligamentum hepatocolicum [TA] .
hepatoduodenal l. [TA] the portion of the lesser omentum that connects the liver and duodenum. SYN: ligamentum hepatoduodenale [TA] .
hepatoesophageal l. [TA] the part of the lesser omentum that extends between the liver and the abdominal part of the esophagus. SYN: ligamentum hepatoesophageum [TA] .
hepatogastric l. [TA] the part of the lesser omentum that extends between the liver and lesser curvature of the stomach. SYN: ligamentum hepatogastricum [TA] .
hepatorenal l. [TA] a prolongation of the coronary l. downward over the right kidney. SYN: ligamentum hepatorenale [TA] .
Hesselbach l. SYN: interfoveolar l..
Hey l. SYN: superior horn of falciform margin of saphenous opening.
Holl l. l. joining the corpora cavernosa clitoridis in front of the urinary meatus.
Hueck l. SYN: trabecular tissue of sclera.
Humphry l. SYN: anterior meniscofemoral l..
Hunter l. SYN: round l. of uterus.
hyalocapsular l. attachment of the vitreous body to the posterior surface of the lens of the eye. SYN: ligamentum hyaloideo-capsulare.
hyoepiglottic l. [TA] a short elastic band that unites the epiglottis to the upper border of the hyoid bone. SYN: ligamentum hyoepiglotticum [TA] .
hypsiloid l. SYN: iliofemoral l..
iliofemoral l. [TA] a triangular l. attached by its apex to the anterior inferior spine of the ilium and rim of the acetabulum, and by its base to the anterior intertrochanteric line of the femur; the strong medial band is attached to the lower part of the intertrochanteric line; the strong lateral part is fixed to the tubercle at the upper part of this line; the bands diverge, forming a Y-like figure with a weak area between; among the strongest of the body's ligaments, it limits extension at the hip joint. SYN: ligamentum iliofemorale [TA] , Bertin l., Bigelow l., hypsiloid l., Y-shaped l..
iliolumbar l. [TA] the strong l. that connects the fourth and fifth lumbar vertebrae with the ilium, spanning the “notch” between the vertebral column and the wing of the ilium. SYN: ligamentum iliolumbale [TA] .
iliopectineal l. SYN: iliopectineal arch.
iliotrochanteric l. the lateral strong band of the Y-shaped iliofemoral l.; it is attached below to the tubercle at the upper part of the intertrochanteric line.
inferior calcaneonavicular l. SYN: plantar calcaneonavicular l..
inferior l. of epididymis [TA] the lower of the folds of the tunica vaginalis between the body of the epididymis and the testis. SYN: ligamentum epididymidis inferius [TA] .
inferior pubic l. [TA] the l. that arches across the inferior aspect of the pubic symphysis. SYN: ligamentum pubicum inferius [TA] , arcuate pubic l., ligamentum arcuatum pubis.
inferior transverse scapular l. [TA] an inconstant fibrous band that passes from the lateral border of the spine of the scapula to the posterior margin of the glenoid cavity. SYN: ligamentum transversum scapulae inferius [TA] , spinoglenoid l..
infundibulo-ovarian l. SYN: ovarian fimbria.
infundibulopelvic l. SYN: suspensory l. of ovary.
inguinal l. [TA] a fibrous band formed by the thickened inferior border of the aponeurosis of the external oblique that extends from the anterior superior spine of the ilium to the pubic tubercle, bridging muscular and vascular lacunae; forms the floor of the inguinal canal; gives origin to the lowermost fibers of internal oblique and transversus abdominis muscles. SEE ALSO: aponeurosis of external oblique muscle. SYN: ligamentum inguinale [TA] , arcus inguinalis&star, crural arch, fallopian arch, fallopian l., femoral arch, Poupart l..
inguinal l. of the kidney the segment of the mesonephros extending to the inguinal region.
intercarpal ligaments [TA] three sets of short fibrous bands that bind together the two rows of carpal bones; according to their location they are named dorsal intercarpal ligaments (ligamenta intercarpalia dorsalia), interosseous intercarpal ligaments (ligamenta intercarpalia interossea), and palmar intercarpal ligaments (ligamenta intercarpalia palmaria). SYN: ligamenta intercarpalia [TA] .
interclavicular l. [TA] a strong l. that connects the two sternoclavicular joints across the upper border of the manubrium. SYN: ligamentum interclaviculare [TA] .
interclinoid l. a band of dura mater connecting the anterior and posterior clinoid processes of the sphenoid bone; may become ossified.
intercornual l. SYN: lateral sacrococcygeal l..
intercostal ligaments SYN: intercostal membranes, under membrane.
intercuneiform ligaments [TA] fibrous bands that unite the cuneiform bones; they are arranged in three sets: dorsal intercuneiform ligaments (ligamenta intercuneiformia dorsalia), interosseous intercuneiform ligaments (ligamenta intercuneiformia interossea), and plantar intercuneiform ligaments (ligamenta intercuneiformia plantaria). SYN: ligamenta intercuneiformia [TA] .
interfoveolar l. [TA] fibrous or muscular strands that lie medial to the deep inguinal ring, extending from the lower border of the transversus muscle to the lacunar l. and pectineal fascia. SYN: ligamentum interfoveolare [TA] , Hesselbach l..
internal collateral l. of the wrist SYN: ulnar collateral l. of wrist joint.
interosseous cuneocuboid l. SYN: cuneocuboid interosseous l..
interosseous cuneometatarsal ligaments SYN: cuneometatarsal interosseous ligaments.
interosseous metacarpal ligaments [TA] fibrous bands connecting the bases of metacarpals two to five; they extend between the dorsal and palmar metacarpal ligaments. SYN: ligamenta metacarpalia interossea [TA] .
interosseous metatarsal ligaments SYN: metatarsal interosseous ligaments.
interosseous sacroiliac ligaments [TA] short obliquely directed fibrous bands that pass between the sacrum and ilium in the narrow cleft behind the auricular surfaces of these bones. SYN: ligamenta sacroiliaca interossea [TA] .
interosseous talocalcaneal l. SYN: talocalcaneal interosseous l..
interosseous tibiofibular l. the distal continuation of the interosseous membrane forming a strong l. that unites the distal end of the tibia and fibula; it lies deep to the posterior tibiofibular l.. SYN: transverse tibiofibular l..
interspinous l. [TA] bands of fibrous tissue that connect the spinous processes of adjacent vertebrae. SYN: ligamentum interspinale [TA] .
intertransverse l. [TA] one of the ligaments that connect the transverse processes of adjacent vertebrae. SYN: ligamentum intertransversarium [TA] .
intraarticular l. of costal head SYN: intraarticular l. of head of rib.
intraarticular l. of head of rib [TA] transverse fibers extending within the capsule from the ridge between the two facets on the head of the rib to the intervertebral disk. SYN: intraarticular l. of costal head, ligamentum capitis costae intraarticulare.
intraarticular sternocostal l. [TA] a l. within the articular capsule between a costal cartilage and the sternum; especially well developed at second costal cartilage. SYN: ligamentum sternocostale intraarticulare [TA] .
intracapsular ligaments [TA] ligaments located within and separate from the articular capsule of a synovial joint. SYN: ligamenta intracapsularia [TA] .
ischiocapsular l. SYN: ischiofemoral l..
ischiofemoral l. [TA] the thickened part of the capsule of the hip joint that passes from the ischium upward and laterally over the femoral neck; some of its fibers continue into the zona orbicularis. SYN: ligamentum ischiofemorale [TA] , ischiocapsular l., ligamentum ischiocapsulare.
jugal l. SYN: cricopharyngeal l..
Krause l. SYN: transverse perineal l..
laciniate l. SYN: flexor retinaculum of lower limb.
lacunar l. [TA] a curved fibrous band that passes horizontally backward from the medial end of the inguinal l. to the pectineal line; it forms the medial boundary of the femoral ring. SEE ALSO: aponeurosis of external oblique muscle. SYN: ligamentum lacunare [TA] , Gimbernat l..
Lannelongue ligaments SYN: sternopericardial ligaments.
lateral l. of ankle [TA] the calcaneofibular l., anterior talofibular l., and posterior talofibular l. together maintaining the integrity of the lateral aspect of the talocrural joint. SYN: ligamentum collaterale laterale [TA] , fibular collateral l. of ankle, lateral collateral l. of ankle.
lateral arcuate l. [TA] a thickening of the fascia of the quadratus lumborum muscle between the transverse process of the first lumbar vertebra and the twelfth rib on either side that gives attachment to a portion of the diaphragm (one of the Haller arches). SYN: ligamentum arcuatum laterale [TA] , arcus lumbocostalis lateralis, lateral lumbocostal arch.
lateral l. of bladder condensations of fibroareolar tissue that pass one from each side of the bladder to blend with the pelvic fascia; smooth muscle is usually present in this tissue and is referred to as the rectovesicalis (musculus rectovesicalis). SYN: ligamentum laterale vesicae [TA] .
lateral collateral l. of ankle SYN: lateral l. of ankle.
lateral costotransverse l. [TA] the short quadrangular l., actually a thickening of the posterior aspect of the costotransverse joint, extending from the tip of the transverse process to the posterior surface of the neck of the rib. SYN: ligamentum costotransversarium laterale [TA] , ligamentum costotransversarium posterius, ligamentum tuberculi costae, posterior costotransverse l..
lateral l. of elbow SYN: radial collateral l. of elbow joint.
lateral l. of knee SYN: fibular collateral l..
lateral malleolar l. See anterior tibiofibular l., posterior tibiofibular l..
lateral l. of malleus [TA] a short fan-shaped l. converging from the posterior half of the tympanic notch to the neck of the malleus. SYN: ligamentum mallei laterale [TA] .
lateral palpebral l. [TA] the band that attaches the tarsal plates to the orbital eminence of the zygomatic bone. SYN: ligamentum palpebrale laterale [TA] , ligamentum palpebrale externum, ligamentum tarsale externum.
lateral puboprostatic l. puboprostatic l.. See puboprostatic l..
lateral sacrococcygeal l. [TA] a l. that extends from the lateral inferior margin of the sacrum to the transverse process of the first coccygeal vertebra. SYN: ligamentum sacrococcygeum laterale [TA] , intercornual l..
lateral talocalcaneal l. [TA] a l. extending from the trochlea of the talus to the lateral surface of the calcaneus. SYN: ligamentum talocalcaneum laterale [TA] .
lateral temporomandibular l. SYN: lateral l. of temporomandibular joint.
lateral l. of temporomandibular joint [TA] the capsular l. that passes obliquely down and backward across the lateral surface of the temporomandibular joint. SYN: ligamentum laterale articulationis temporomandibularis [TA] , Ferrein l., lateral temporomandibular l., ligamentum temporomandibulare, temporomandibular l..
lateral thyrohyoid l. [TA] thickened elastic bundle connecting the superior horn of the thyroid cartilage to the tip of the greater horn of the hyoid cartilage; forms the posterior border of the thyrohyoid membrane. SYN: ligamentum thyrohyoideum laterale [TA] , Berry ligaments, ligamentum hyothyroideum laterale.
lateral umbilical l. SYN: ligamentum umbilicale laterale.
lateral l. of wrist SYN: radial collateral l. of wrist joint.
Lauth l. SYN: transverse l. of the atlas.
l. of left superior vena cava the obliterated left common cardinal vein that extends from the left brachiocephalic vein to the oblique vein of the left atrium.
left triangular l. of liver [TA] a triangular fold of fibrous connective tissue and peritoneum that extends from the left lobe of the liver to the diaphragm. SYN: ligamentum triangulare sinistrum hepatis [TA] .
l. of left vena cava [TA] the obliterated left common cardinal vein; it extends from the left brachiocephalic vein to the oblique vein of the left atrium. SYN: ligamentum venae cavae sinistrae [TA] .
lienophrenic l. SYN: phrenicosplenic l..
lienorenal l. splenorenal l..
Lisfranc ligaments SYN: cuneometatarsal interosseous ligaments.
Lockwood l. SYN: suspensory l. of eyeball.
longitudinal ligaments one of two extensive fibrous bands running the length of the vertebral column: the anterior longitudinal l. and the posterior longitudinal l.. SEE ALSO: anterior longitudinal l., posterior longitudinal l.. SYN: ligamenta longitudinalia.
long plantar l. [TA] a strong l. that extends from the calcaneus to the cuboid and lateral metatarsals on the plantar aspect of the foot; part of the passive support system for maintaining the longitudinal arch of the foot. SYN: ligamentum plantare longum [TA] .
lumbocostal l. [TA] a strong band that unites the twelfth rib with the tips of the transverse processes of the first and second lumbar vertebrae. SYN: ligamentum lumbocostale [TA] .
Luschka ligaments SYN: sternopericardial ligaments.
Mackenrodt l. SYN: cardinal l..
ligaments of malleus anterior l. of malleus, lateral l. of malleus, superior l. of malleus.
Mauchart ligaments alar ligaments.
Meckel l. SYN: Meckel band.
medial l. of ankle joint [TA] compound l. consisting of four component ligaments which pass downward from the medial malleolus of the tibia to the tarsal bones: 1) tibionavicular l. (pars tibionavicularis [NA]), 2) tibiocalcaneal l. (pars tibiocalcanea [NA]), 3) anterior tibiotalar l. (pars tibiotalaris anterior [NA]), and 4) posterior tibiotalar l. (pars tibiotalaris posterior [NA]). SYN: ligamentum collaterale mediale [TA] , deltoid l.&star, ligamentum deltoideum&star, ligamentum mediale articulationis talocruralis, medial l. of talocrural joint, tibial collateral l. of ankle joint.
medial arcuate l. [TA] one of Haller arches; a tendinous thickening of the psoas fascia that extends from the body of the first lumbar vertebra to its transverse process on either side. A portion of the diaphragm arises from it. SYN: ligamentum arcuatum mediale [TA] , arcus lumbocostalis medialis, medial lumbocostal arch.
medial canthal l. SYN: medial palpebral l..
medial collateral l. of elbow SYN: ulnar collateral l. of elbow joint.
medial l. of knee SYN: tibial collateral l..
medial palpebral l. [TA] the fibrous band that attaches the medial ends of the tarsal plates to the maxilla at the medial orbital margin. SYN: ligamentum palpebrale mediale [TA] , ligamentum tarsale internum, medial canthal l., tendo oculi, tendo palpebrarum.
medial puboprostatic l. pubovesical l. (of male).
medial talocalcaneal l. [TA] a l. extending from the medial tuberosity of the posterior talar process and the sustentaculum tali. SYN: ligamentum talocalcaneum mediale [TA] .
medial l. of talocrural joint SYN: medial l. of ankle joint.
medial l. of temporomandibular joint [TA] the intracapsular bundle of fibers strengthening the medial part of the articular capsule of the temporomandibular joint; not as apparent as the lateral l.. SYN: ligamentum mediale articulationis temporomandibularis [TA] .
medial umbilical l. SYN: cord of umbilical artery.
medial l. of wrist SYN: ulnar collateral l. of wrist joint.
median arcuate l. [TA] a tendinous connection between the crura of the diaphragm that arches over the aorta, forming the anterosuperior margin of the aortic hiatus. SYN: ligamentum arcuatum medianum [TA] .
median cricothyroid l. [TA] the strong band that connects the cricoid and thyroid cartilages in the midline anteriorly; it is continuous posteriorly with the conus elasticus.
median thyrohyoid l. [TA] the central thickened portion of the thyrohyoid membrane. SYN: ligamentum thyrohyoideum medianum [TA] , ligamentum hyothyroideum medium.
median umbilical l. [TA] the remnant of the urachus, contained in the median umbilical fold; it persists as a midline fibrous cord between the apex of the bladder and the umbilicus. SYN: ligamentum umbilicale medianum [TA] , middle umbilical l., urachal l..
meniscofemoral ligaments [TA] one of two ligaments that extend from the posterior part of the lateral meniscus to the lateral surface of the medial meniscus: anterior meniscofemoral l. and posterior meniscofemoral l.. SEE ALSO: anterior meniscofemoral l., posterior meniscofemoral l.. SYN: ligamenta meniscofemoralia [TA] .
metatarsal interosseous ligaments [TA] fibrous bands that connect the bases of the metatarsals; they extend between the dorsal and plantar metatarsal ligaments. SYN: ligamenta metatarsalia interossea [TA] , interosseous metatarsal ligaments.
middle costotransverse l. SYN: costotransverse l..
middle umbilical l. SYN: median umbilical l..
nuchal l. ligamentum nuchae.
oblique l. of elbow joint SYN: oblique cord of interosseous membrane of forearm.
oblique popliteal l. [TA] reflected tendon of insertion of semimembranous muscle; a fibrous band that extends across the back of the knee from its separation from the direct tendon of insertion on the medial condyle of the tibia to the lateral condyle of the femur. SYN: ligamentum popliteum obliquum [TA] , Bourgery l..
occipitoaxial ligaments ligaments connecting the axis with the occipital bone. See alar ligaments, apical l. of dens.
orbicular l. SYN: anular l..
orbicular l. of radius SYN: anular l. of radius.
ovarian l. SYN: l. of ovary.
l. of ovary [TA] a cordlike bundle of fibers passing to the side of the uterus from the lower end of the ovary, between the folds of the broad l. (mesovarium). SYN: ligamentum ovarii proprium [TA] , ligamentum uteroovaricum&star, ovarian l., proper l. of ovary.
palmar ligaments [TA] the fibrocartilaginous plates, one located on the anterior aspect of each metacarpophalangeal and interphalangeal joint of the hand, that are firmly attached to the bases of the phalanges and the heads of the next proximal bones; they are grooved to accommodate the long flexor tendons. SEE ALSO: palmar ligaments of interphalangeal joints of hand, palmar ligaments of metacarpophalangeal joints. SYN: ligamenta palmaria [TA] , accessory volar ligaments.
palmar carpal l. SYN: antebrachial flexor retinaculum.
palmar carpometacarpal ligaments [TA] fibrous bands that connect the palmar surfaces of the carpal and metacarpal bones. SYN: ligamenta carpometacarpalia palmaria [TA] .
palmar ligaments of interphalangeal joints of hand [TA] ligaments located on the anterior (palmar) aspect of the interphalangeal joints of the fingers, flanked by and connected to the collateral ligaments, forming the anterior portion of the joint capsule; lighter but similar in structure and function to the palmar ligaments of metacarpophalangeal joints. SEE ALSO: palmar ligaments of metacarpophalangeal joints. SYN: ligamenta palmaria articulationis interphalangeae manus [TA] .
palmar metacarpal ligaments [TA] fibrous bands connecting the palmar aspects of the bases of metacarpals two to five. SYN: ligamenta metacarpalia palmaria [TA] .
palmar ligaments of metacarpophalangeal joints [TA] thick, dense, fibrocartilaginous ligaments located on the anterior (palmar) aspect of the metacarpophalangeal joints, flanked by and connected to the collateral ligaments, forming the anterior portion of the joint capsule; the ligaments are grooved longitudinally (relative to the digit) to accommodate the long flexor tendons of the digit; on each side of the groove they are attached to both the deep transverse metacarpal ligaments and fibrous sheaths of the fingers; they are firmly attached to the base of the proximal phalanges, deepening the “socket” of the phalangeal bases to accommodate the heads of the metacarpals, to which they are loosely attached, permitting free movement. SYN: ligamenta palmaria articulationis metacarpophalangeae [TA] , palmar plates.
palmar radiocarpal l. [TA] a strong l. that passes from the distal end of the radius to the proximal row of carpal bones on the anterior surface of the wrist joint. SYN: ligamentum radiocarpale palmare [TA] .
palmar ulnocarpal l. [TA] the fibrous band that passes from the ulnar styloid process to the carpal bones. SYN: ligamentum ulnocarpale palmare [TA] .
patellar l. [TA] a strong flattened fibrous band passing from the apex and adjoining margins of the patella to the tuberosity of the tibia; considered by some to be part of the tendon of the quadriceps femoris muscle, in which the patella is embedded as a sesamoid bone. SYN: ligamentum patellae [TA] .
pectinate ligaments of iridocorneal angle SYN: trabecular tissue of sclera.
pectinate ligaments of iris See trabecular tissue of sclera.
pectineal l. [TA] a thick, strong fibrous band that passes laterally from the lacunar l. along the pectineal line of the pubis. This fibrous tissue on the bony surface allows the purchase of sutures in various procedures to repair inguinal herniae. SEE ALSO: aponeurosis of external oblique muscle. SYN: ligamentum pectineale [TA] , Cooper ligaments (2) .
peridental l. SYN: periodontium.
periodontal l. [TA] SYN: periodontium.
phrenicocolic l. [TA] a triangular fold of peritoneum attached to the left flexure of the colon and to the diaphragm, on which rests the inferior pole or extremity of the spleen. SYN: ligamentum phrenicocolicum [TA] , costocolic l..
phrenicolienal l. SYN: phrenicosplenic l..
phrenicosplenic l. [TA] double fold of peritoneum (mesentery) extending between the diaphragm and spleen; this is a portion of the greater omentum, and distinctions between the phrenicosplenic l. and adjacent ligaments, such as the gastrophrenic, gastrosplenic and splenorenal ligaments—all part of the same mesenteric sheet—are often nebulous. SYN: ligamentum phrenicosplenicum [TA] , lienophrenic l., ligamentum phrenicolienale, phrenicolienal l., phrenosplenic l., sustentaculum lienis.
phrenogastric l. SYN: gastrophrenic l..
phrenosplenic l. SYN: phrenicosplenic l..
pisohamate l. [TA] a strong fibrous band that extends from the pisiform bone to the hook of the hamate. SYN: ligamentum pisohamatum [TA] , pisounciform l., pisouncinate l..
pisometacarpal l. [TA] a strong fibrous band extending from the pisiform bone to the base of the fifth metacarpal bone; this l., together with the pisohamate l., forms the tendon of insertion of the flexor carpi ulnaris, in which the pisiform bone is like a sesamoid bone. SYN: ligamentum pisometacarpeum [TA] .
pisounciform l. SYN: pisohamate l..
pisouncinate l. SYN: pisohamate l..
plantar ligaments [TA] fibrocartilaginous plates located on the plantar aspect of each metatarsophalangeal and interphalangeal joint of the foot; the counterparts in the foot of the palmar ligaments in the hand. SEE ALSO: plantar ligaments of interphalangeal joints of foot, plantar ligaments of metatarsophalangeal joints. SYN: ligamenta plantaria [TA] , accessory plantar ligaments, Cruveilhier ligaments, glenoid l. (2) .
plantar calcaneocuboid l. [TA] a strong band that passes forward and medially from the plantar surface of the calcaneus to the cuboid bone, actually forming a part of the articular capsule of the calcaneocuboid joint; the shorter, deeper portion of the long plantar l.. SYN: ligamentum calcaneocuboideum plantare [TA] .
plantar calcaneonavicular l. [TA] a dense fibroelastic l. that extends from the sustentaculum tali to the plantar surface of the navicular bone; it supports the head of the talus, actually forming part of the articular “socket” for the head of the talus. SYN: ligamentum calcaneonaviculare plantare [TA] , spring l.&star, inferior calcaneonavicular l..
plantar cuboideonavicular ligaments [TA] the ligaments that unite the plantar surfaces of the cuboid and navicular bones of the tarsus. SYN: ligamenta cuboideonavicularia plantaria [TA] .
plantar cuneocuboid l. [TA] the fibrous band that unites the apex of the lateral cuneiform with the medial margin of the plantar suface of the cuboid. SYN: ligamentum cuneocuboideum plantare [TA] .
plantar cuneonavicular ligaments [TA] ligaments connecting the plantar surface of the navicular with the three cuneiform bones. SYN: ligamenta cuneonavicularia plantaria [TA] .
plantar ligaments of interphalangeal joints of foot [TA] ligaments located on the inferior (sole) aspect of the interphalangeal joints of the toes, flanked by and connected to the collateral ligaments, forming the plantar portion of the joint capsule; lighter but similar in structure and function to the palmar ligaments of metacarpophalangeal joints. SEE ALSO: plantar ligaments of metatarsophalangeal joints. SYN: ligamenta plantaria articulationis interphalangeae pedis [TA] .
plantar ligaments of metatarsophalangeal joints [TA] thick, dense ligaments located on the inferior (sole) aspect of the metatarsophalangeal joints, flanked by and connected to the collateral ligaments, forming the plantar portion of the joint capsule; the ligaments are grooved longitudinally (relative to the digit) to accommodate the long flexor tendons of the digit; on each side of the groove they are attached to both the deep transverse metatarsal ligaments and fibrous sheaths of the toes; they are firmly attached to the base of the proximal phalanges, deepening the “socket” of the phalangeal bases to accommodate the heads of the metatarsals, to which they are loosely attached, permitting free movement. SYN: ligamenta plantaria articulationis metatarsophalangeae [TA] .
plantar metatarsal ligaments [TA] fibrous bands connecting the plantar aspects of the bases of the metatarsals. SYN: ligamenta metatarsalia plantaria [TA] .
plantar tarsal ligaments [TA] ligaments connecting plantar aspects of the tarsal bones as a group; included in the group are the: long plantar l. [TA] (ligamentum plantare longum [TA]), and the following plantar ligaments (ligamentum/a . . . plantare/ia): calcaneocuboid [TA] (calcaneocuboideum [TA]), calcaneonavicular [TA] (calcaneonaviculare [TA]), cuneonavicular [TA] (cuneonavicularia [TA]), cuboideonavicular [TA] (cuboideonaviculare [TA]), intercuneiform [TA] (intercuneiformia [TA]), and cuneocuboid [TA] (cuneocuboideum [TA]). SYN: ligamenta tarsi plantaria [TA] .
plantar tarsometatarsal ligaments [TA] longitudinal and oblique bands reinforcing the plantar aspects of the tarsometatarsal joints (joints between the metatarsals and the cuboid and cuneiform bones); the medial bands are strongest; they become progressively weaker laterally. SYN: ligamenta tarsometatarsalia plantaria [TA] .
posterior costotransverse l. SYN: lateral costotransverse l..
posterior cricoarytenoid l. SYN: cricoarytenoid l..
posterior cruciate l. [TA] the strong fibrous cord that extends from the posterior intercondylar area of the tibia to the anterior part of the lateral surface of the medial condyle of the femur. SYN: ligamentum cruciatum posterius [TA] .
posterior l. of fibular head [TA] a l. uniting the posterior part of the head of the fibula to the tibia. SYN: ligamentum capitis fibulae posterius [TA] , posterior l. of head of fibula.
posterior l. of head of fibula SYN: posterior l. of fibular head.
posterior l. of incus [TA] ligamentous band extending from short crus of incus. SYN: ligamentum incudis posterius [TA] .
posterior l. of knee SYN: arcuate popliteal l..
posterior longitudinal l. [TA] the fibrous band interconnecting the posterior surfaces of the vertebral bodies; it narrows to pass between the pedicles and spreads out to blend with the outer lamellae of the posterior aspect of the anulus fibrosus of the intervertebral disks; forms the anterior wall of the vertebral canal. SYN: ligamentum longitudinale posterius [TA] .
posterior meniscofemoral l. [TA] the band that passes posterior to the posterior cruciate l. extending between the medial condyle of the femur and the posterior crus of the lateral meniscus. SYN: ligamentum meniscofemorale posterius [TA] , ligamentum cruciatum tertium genus, ligamentum menisci lateralis, Wrisberg l..
posterior occipitoaxial l. SYN: tectorial membrane (of median atlantoaxial joint).
posterior sacroiliac ligaments [TA] the heavy fibrous bands that pass from the ilium to the sacrum posterior to the sacroiliac joint. SYN: ligamenta sacroiliaca posteriora [TA] , dorsal sacroiliac ligaments, ligamentum sacroiliacum posterius.
posterior sacrosciatic l. SYN: sacrotuberous l..
posterior sternoclavicular l. [TA] a fibrous band that reinforces the sternoclavicular joint posteriorly. SYN: ligamentum sternoclaviculare posterius [TA] .
posterior talocalcaneal l. [TA] stout l. located immediately posterior to the lateral portion of the talocalcaneal interosseous l. and medial to the lateral talocalcaneal l. in the widest part of the tarsal sinus. SYN: ligamentum talocalcaneum posterius [TA] .
posterior talofibular l. [TA] the nearly horizontal fibrous band that extends from the posterior border of the talus to the malleolar fossa. SYN: ligamentum talofibulare posterius [TA] .
posterior talotibial l. SYN: tibiotalar part of medial l. of ankle joint. SEE ALSO: medial l. of ankle joint.
posterior tibiofibular l. [TA] the fibrous band that horizontally crosses the posterior aspect of the tibiofibular syndesmosis, contributing the posterior “wall” of the “socket” which receives the trochlea of the talus. SYN: ligamentum tibiofibulare posterius [TA] .
posterior tibiotalar l. SYN: tibiotalar part of medial l. of ankle joint.
Poupart l. SYN: inguinal l..
proper l. of ovary SYN: l. of ovary.
pterygomandibular l. SYN: pterygomandibular raphe.
pterygospinal l. SYN: pterygospinous l..
pterygospinous l. [TA] a membranous l. extending from the spine of the sphenoid to the upper part of the posterior border of the lateral plate of the sphenoid (lateral pterygoid plate). SYN: ligamentum pterygospinale [TA] , Civinini l., pterygospinal l..
pubocapsular l. SYN: pubofemoral l..
pubofemoral l. [TA] a thickened part of the capsule of the hip joint that extends from the superior ramus of the pubis to the intertrochanteric line of the femur. SYN: ligamentum pubofemorale [TA] , ligamentum pubocapsulare, pubocapsular l..
puboprostatic l. [TA] the localized thickening of the superior fascia of the pelvic diaphragm anteriorly that anchors the prostate and neck of the bladder to the pubis on each side. It usually contains smooth muscle. SYN: ligamentum puboprostaticum [TA] , lateral puboprostatic l.&star, Denonvilliers l..
pubovesical l. (of female) [TA] in the female the fascial thickening comparable with the puboprostatic l. composed of medial and lateral pubovesical ligaments. SYN: ligamentum pubovesicale (femininum) [TA] .
pubovesical l. (of male) [TA] anteriormost portion of the tendinous arch of the pelvic fascia (a condensation of the superior fascia of the pelvic diaphragm) extending between the lower part of the pubic symphysis and the prostate and bladder; it forms the inferior boundary of the potential retropubic (prevesical) space. SYN: ligamentum pubovesicale (masculinum) [TA] , ligamentum mediale puboprostaticum&star, medial puboprostatic l.&star.
pulmonary l. [TA] two-layered fold formed as the pleura of the mediastinum is reflected onto the lung inferior to the root of the lung. SYN: ligamentum pulmonale [TA] , ligamentum latum pulmonis, Teutleben l..
quadrate l. [TA] fibers that pass from the distal margin of the radial notch of the ulna to the neck of the radius. SYN: ligamentum quadratum [TA] , Denucé l..
radial collateral l. SYN: radial collateral l. of elbow joint.
radial collateral l. of elbow joint [TA] the l. that connects the lateral epicondyle of the humerus with the anular l. of the radius. SYN: ligamentum collaterale radiale articulationis cubiti [TA] , lateral l. of elbow, radial collateral l..
radial collateral l. of wrist joint [TA] the l. that extends distally from the styloid process of the radius to the carpal bones. SYN: ligamentum collaterale carpi radiale articulationis radiocarpalis [TA] , external collateral l. of wrist, lateral l. of wrist.
radiate l. SYN: radiate l. of head of rib.
radiate carpal l. [TA] the l. that extends from the capitate bone to the scaphoid, lunate, and triquetrum on the palmar side of the wrist. SYN: ligamentum carpi radiatum [TA] , radiate l. of wrist.
radiate l. of head of rib [TA] the radiate, stellate, or anterior costovertebral l. connecting the head of each rib to the bodies of the two vertebrae with which it articulates. SYN: ligamentum capitis costae radiatum [TA] , ligamentum radiatum, radiate l., stellate l..
radiate sternocostal ligaments [TA] fibers of the articular capsule that radiate from the costal cartilages to the anterior surface of the sternum. SYN: ligamenta sternocostalia radiata [TA] .
radiate l. of wrist SYN: radiate carpal l..
reflected inguinal l. [TA] slightly reinforced portion of the external oblique aponeurosis, formed by fibers derived from the medial portion of the inguinal l. of one side that run medially and slightly superiorly, defining the inferior margin of the superficial inguinal ring; the fibers then pass on the deep aspect of the ipsilateral medial crus, crossing the linea alba and running within the contralateral aponeurosis to course parallel and superior to the contralateral inguinal l.. SEE ALSO: aponeurosis of external oblique muscle. SYN: ligamentum reflexum [TA] , Colles l., fascia triangularis abdominis, reflex l., triangular fascia.
reflex l. SYN: reflected inguinal l..
Retzius l. the deep attachment of the inferior extensor retinaculum in the tarsal sinus, it acts as a sling for the extensor tendons of the toes. SYN: fundiform l. of foot.
rhomboid l. SYN: costoclavicular l..
right triangular l. of liver [TA] a triangular fold of peritoneum that passes from the right lobe of the liver to the diaphragm; it is a formation of the coronary l., formed as the coronary l. makes an acute angle upon reaching its most lateral point on the right side as it surrounds the bare area of the liver. SYN: ligamentum triangulare dextrum hepatis [TA] .
ring l. SYN: zona orbicularis (articulationis coxae).
round l. of elbow joint SYN: oblique cord of interosseous membrane of forearm.
round l. of femur SYN: l. of head of femur.
round l. of liver [TA] the remains of the umbilical vein running within the free edge of the falciform l. from umbilicus to the liver, where it continues within the fissure for the round l. to the origin of the left portal vein within the porta hepatis. SYN: ligamentum teres hepatis [TA] .
round l. of uterus [TA] a fibromuscular band that is attached to the uterus on either side in front of and below the opening of the uterine tube; it passes through the inguinal canal to the labium majus; corresponds to the spermatic cord of male in that it passes through the inguinal canal and gains similar coverings, but is not homologous, being a homolog of the gubernaculum testis. SYN: ligamentum teres uteri [TA] , Hunter l..
sacrodural l. a longitudinal bundle of fibrous filaments running from the midline of the inferior part of the dural sac to the posterior longitudinal l. of the sacrum. SYN: ligamentum sacrodurale.
sacrospinous l. [TA] the fibrous band that passes from the ischial spine to the sacrum and coccyx. SYN: ligamentum sacrospinale [TA] , anterior sacrosciatic l., ligamentum sacrospinosum.
sacrotuberous l. [TA] the l. that passes from the ischial tuberosity to the ilium, sacrum, and coccyx, transforming the sciatic notch to a large sciatic foramen, which is then further subdivided by the sacrospinous l.. SYN: ligamentum sacrotuberale [TA] , ligamentum sacrotuberosum, posterior sacrosciatic l..
serous l. one of a number of peritoneal folds attaching certain of the viscera to the abdominal wall or to each other. SYN: ligamentum serosum.
sheath ligaments fibrous sheaths of digits of hand, under sheath, fibrous digital sheaths of toes, under sheath, fibrous tendon sheath.
Simonart ligaments SYN: amnionic band.
skin ligaments [TA] one of the numerous small fibrous strands that extend through the superficial fascia attaching the deep surface of the dermis to the underlying deep fascia determining the mobility of the skin over the deep structures; these are particularly well developed over the breast where they are known as suspensory ligaments of the breast; they are also well-developed, but short, in the palms and soles. SYN: retinaculum cutis [TA] , retinaculum of skin.
Soemmerring l. small fibers attaching the lacrimal gland to the periorbita.
sphenomandibular l. [TA] the fibrous band that passes from the spine of the sphenoid bone to the lingula of the mandible; it is a primary passive support of the mandible serving as a “swinging axis”, permitting depression and elevation around a transverse axis passing through the two lingulae, while at the same time permitting protraction and retraction. SYN: ligamentum sphenomandibulare [TA] .
spinoglenoid l. SYN: inferior transverse scapular l..
spiral l. of cochlea SYN: spiral l. of cochlear duct.
spiral l. of cochlear duct [TA] the thickened periosteal lining of the bony cochlea forming the outer wall of the cochlear duct to which the basal lamina attaches. SYN: ligamentum spirale ductus cochlearis [TA] , crista spiralis, ligamentum spirale cochleae, spiral crest, spiral l. of cochlea.
splenorenal l. [TA] a peritoneal fold (portion of the greater omentum) that extends from the anterior aspect of the left kidney to the splenic hilum, conducting the splenic vessels from the posterior body wall to the spleen. SYN: ligamentum splenorenale [TA] , lienorenal l.&star, ligamentum lienorenale&star.
spring l. plantar calcaneonavicular l..
Stanley cervical ligaments fibers of the capsule of the hip joint reflected onto the neck of the femur.
stellate l. SYN: radiate l. of head of rib.
sternoclavicular ligaments l. uniting the clavicle to the manubrium of the sternum. See anterior sternoclavicular l., posterior sternoclavicular l.. SYN: ligamenta sternoclavicularia.
sternopericardial ligaments fibrous bands that pass from the pericardium to the sternum. SYN: ligamenta sternopericardiaca [TA] , Lannelongue ligaments, Luschka ligaments.
stylohyoid l. [TA] a fibrous cord that passes from the tip of the styloid process to the lesser cornu of the hyoid bone; it is occasionally ossified. SYN: ligamentum stylohyoideum [TA] , epihyal l..
stylomandibular l. [TA] a condensation of the deep cervical fascia extending from the tip of the styloid process of the temporal bone to the posterior border of the angle of the jaw; blends with (is a thickening of) the parotid sheath. SYN: ligamentum stylomandibulare [TA] , stylomaxillary l..
stylomaxillary l. SYN: stylomandibular l..
superficial dorsal sacrococcygeal l. SYN: superficial posterior sacrococcygeal l..
superficial posterior sacrococcygeal l. [TA] the continuation of the supraspinal l. from the sacrum to the coccyx. SYN: ligamentum sacrococcygeum posterius superficiale [TA] , ligamentum sacrococcygeum dorsale superficiale&star, superficial dorsal sacrococcygeal l..
superficial transverse metacarpal l. [TA] a thickening of the deep fascia in the most distal part of the (base) of the triangular palmar aponeurosis. SYN: ligamentum metacarpale transversum superficiale [TA] , Gerdy fibers, ligamentum natatorium.
superficial transverse metatarsal l. [TA] a thickening of the distal part (base) of the plantar aponeurosis, at the level of the heads of the metatarsal bones. SYN: ligamentum metatarsale transversum superficiale [TA] .
superior costotransverse l. [TA] the fibrous band that extends upward from the neck of a rib to the transverse process of the next higher vertebra. SYN: ligamentum costotransversarium superius [TA] , anterior costotransverse l., ligamentum costotransversarium anterius.
superior l. of epididymis [TA] the uppermost of the two folds of the tunica vaginalis between the head of the epididymis and the testis. SYN: ligamentum epididymidis superius [TA] .
superior l. of incus [TA] connects the body of the incus with the roof of the tympanic recess. SYN: ligamentum incudis superius [TA] .
superior l. of malleus [TA] a l. extending from the head of the malleus to the roof of the epitympanic recess. SYN: ligamentum mallei superius [TA] .
superior pubic l. [TA] fibers that pass transversely above the pubic symphysis. SYN: ligamentum pubicum superius [TA] .
superior transverse scapular l. [TA] the strong fibrous band that bridges the scapular notch creating a foramen that gives passage to the suprascapular nerve, while the suprascapular vessels pass over the l. superiorly. SYN: ligamentum transversum scapulae superius [TA] , suprascapular l..
suprascapular l. SYN: superior transverse scapular l..
supraspinous l. [TA] the longitudinal fibrous band attached to the tips of the spinous processes of the vertebrae; in the cervical region it is altered to form the ligamentum nuchae. SYN: ligamentum supraspinale [TA] .
suspensory l. of axilla [TA] the continuation of the clavipectoral fascia downward to attach to the axillary fascia; it maintains the characteristic hollow of the armpit. SYN: ligamentum suspensorium axillae [TA] , Campbell l., Gerdy l..
suspensory ligaments of breast [TA] well-developed retinacula cutis that extend from the fibrous stroma of the mammary gland to the overlying skin. SYN: retinaculum cutis mammae&star, suspensory retinaculum of breast&star, Cooper ligaments (1) , ligamenta suspensoria mammaria, suspensory ligaments of Cooper.
suspensory l. of clitoris [TA] a fibrous band at the deep fascial level that extends from the pubic symphysis to the deep fascia of the clitoris, anchoring the clitoris to the pubic symphysis. SYN: ligamentum suspensorium clitoridis [TA] .
suspensory ligaments of Cooper SYN: suspensory ligaments of breast.
suspensory l. of duodenum suspensory muscle of duodenum.
suspensory l. of esophagus SYN: cricoesophageal tendon.
suspensory l. of eyeball [TA] a thickening of the inferior part of the bulbar sheath that supports the eye within the orbit; it extends between the lateral and medial orbital margins and includes the medial and lateral check ligaments. SYN: ligamentum suspensorium bulbi [TA] , Lockwood l..
suspensory l. of gonad SYN: genital l..
suspensory l. of lens SYN: ciliary zonule.
suspensory l. of ovary [TA] a band of peritoneum that extends upward from the upper pole of the ovary; it contains the ovarian vessels and ovarian plexus of nerves. SYN: ligamentum suspensorium ovarii [TA] , Clado band, infundibulopelvic l..
suspensory l. of penis [TA] a fibrous band at the deep fascial layer that extends from the pubic symphysis to the deep fascia of the penis anchoring the roof of the penis. SYN: ligamentum suspensorium penis [TA] .
suspensory l. of testis the cranial atrophic portion of the urogenital ridge attached to the cranial pole of the intraabdominal embryonic testis.
suspensory l. of thyroid gland [TA] one of several fibrous bands that pass from the sheath of the thyroid gland to the thyroid and cricoid cartilages. SYN: ligamentum suspensorium glandulae thyroideae [TA] .
sutural l. a delicate membrane binding the bones at the cranial sutures.
synovial l. one of the large synovial folds in a joint.
talocalcaneal l. [TA] any of three ligaments uniting the talus and calcaneus: talocalcaneal interosseous l., lateral talocalcaneal l., and medial talocalcaneal l.. SYN: ligamentum talocalcaneum [TA] .
talocalcaneal interosseous l. [TA] a strong fibrous band occupying the tarsal sinus; one of three tarsal interosseous ligaments. SYN: interosseous talocalcaneal l., ligamentum talocalcaneare interosseum.
talonavicular l. [TA] one of the dorsal tarsal ligaments, which occurs as a broad gap that passes from the dorsal side of the neck of the talus to the dorsal surface of the navicular bone. SYN: ligamentum talonaviculare [TA] .
tarsal ligaments [TA] the ligaments that interconnect the tarsal bones; they are grouped into three sets: dorsal tarsal ligaments, interosseous tarsal ligaments, and plantar tarsal ligaments, and are individually named according to their attachments. SYN: ligamenta tarsi [TA] .
tarsal interosseous ligaments [TA] deeper ligaments located between tarsal bones, connecting them together; group includes the talocalcaneal, cuneocuboid, and intercuneiform interosseous ligaments. SYN: ligamenta tarsi interossea [TA] .
tarsometatarsal ligaments [TA] the ligaments that unite tarsal and metatarsal bones; they are arranged in dorsal, plantar, and cuneometatarsal interosseous sets. SYN: ligamenta tarsometatarsalia [TA] .
temporomandibular l. SYN: lateral l. of temporomandibular joint.
Teutleben l. SYN: pulmonary l..
Thompson l. SYN: iliopubic tract.
thyroepiglottic l. [TA] an elastic band that connects the petiole of the epiglottis to the interior of the thyroid cartilage near the superior thyroid notch. SYN: ligamentum thyroepiglotticum [TA] .
tibial collateral l. [TA] the broad fibrous band that passes from the medial epicondyle of the femur to the medial margin and medial surface of the tibia; the medial meniscus is attached to its deep surface; it is continuous with (is a thickening of) the fibrous capsule of the knee joint. SYN: ligamentum collaterale tibiale [TA] , medial l. of knee.
tibial collateral l. of ankle joint SYN: medial l. of ankle joint.
tibiocalcaneal l. SYN: tibiocalcaneal part of medial l. of ankle joint.
tibiofibular l. anterior tibiofibular l., interosseous membrane of leg, posterior tibiofibular l.. SEE ALSO: tibiofibular syndesmosis.
tibionavicular l. SYN: tibionavicular part of medial l. of ankle joint.
transverse acetabular l. [TA] portion of the acetabular labrum that passes across the acetabular notch. SYN: ligamentum transversum acetabuli [TA] , transverse l. of acetabulum.
transverse l. of acetabulum SYN: transverse acetabular l..
transverse atlantal l. SYN: transverse l. of the atlas.
transverse l. of the atlas [TA] thick, strong, centrally flattened band spanning the vertebral foramen of the atlas as it extends from the medial aspect of one lateral mass to the other, passing dorsal to the dens with which it articulates; it forms the dorsal portion of the opening for the dens, tightly embracing its neck. It forms a part of the “cross-bar” of the cruciform l. of the atlas. SEE ALSO: cruciate l. of the atlas. SYN: ligamentum transversum atlantis [TA] , Lauth l., transverse atlantal l..
transverse carpal l. SYN: flexor retinaculum.
transverse cervical l. cardinal l..
transverse crural l. SYN: superior extensor retinaculum.
transverse l. of elbow a bundle of fibers running from the olecranon to the coronoid process in association with the ulnar collateral l.. SYN: Cooper ligaments (3) .
transverse genicular l. SYN: transverse l. of knee.
transverse humeral l. [TA] a fibrous band running more or less obliquely from the greater to the lesser tuberosity of the humerus, bridging over the bicipital groove. SYN: ligamentum transversum humeri [TA] , Brodie l..
transverse l. of knee [TA] a transverse band that passes between the lateral and medial menisci in the anterior part of the knee joint. SYN: ligamentum transversum genus [TA] , transverse genicular l..
transverse l. of leg SYN: superior extensor retinaculum.
transverse metacarpal l. SYN: deep transverse metacarpal l..
transverse metatarsal l. SYN: deep transverse metatarsal l..
transverse l. of pelvis SYN: transverse perineal l..
transverse perineal l. [TA] the thickened anterior border of the perineal membrane. SYN: ligamentum transversum perinei [TA] , Krause l., ligamentum transversum pelvis, transverse l. of pelvis, transverse l. of perineum.
transverse l. of perineum SYN: transverse perineal l..
transverse tibiofibular l. SYN: interosseous tibiofibular l..
trapezoid l. [TA] the lateral part of the coracoclavicular l. that attaches to the trapezoid line of the clavicle. SYN: ligamentum trapezoideum [TA] .
Treitz l. SYN: suspensory muscle of duodenum.
triangular l. SYN: perineal membrane.
triangular ligaments of liver right triangular l. of liver, left triangular l. of liver.
ulnar collateral l. SYN: ulnar collateral l. of elbow joint.
ulnar collateral l. of elbow joint [TA] the triangular l. extending from the medial epicondyle of the humerus to the medial side of the coronoid process and olecranon of the ulna. SYN: ligamentum collaterale ulnare articulationis cubiti [TA] , medial collateral l. of elbow, ulnar collateral l..
ulnar collateral l. of wrist joint [TA] a l. that passes from the styloid process of the ulna to the pisiform and triquetrum. SYN: internal collateral l. of the wrist, ligamentum collaterale carpi ulnare articulationis radiocarpalis, medial l. of wrist.
urachal l. SYN: median umbilical l..
uterovesical l. a peritoneal fold extending from the uterus to the posterior portion of the bladder. SYN: plica uterovesicalis, plica vesicouterina, uterovesical fold, vesicouterine l..
Valsalva ligaments SYN: ligaments of auricle.
venous l. SYN: ligamentum venosum.
ventral sacrococcygeal l. SYN: anterior sacrococcygeal l..
ventral sacroiliac ligaments SYN: anterior sacroiliac ligaments.
ventricular l. SYN: vestibular l..
vertebropelvic ligaments iliolumbar l., sacrospinous l., sacrotuberous l..
vesicoumbilical l. one of the ligaments between the urinary bladder and the umbilicus. See median umbilical l., cord of umbilical artery.
vesicouterine l. SYN: uterovesical l..
vestibular l. [TA] the inferior border of the quadrangular membrane that underlies the ventricular fold of the larynx. SYN: ligamentum vestibulare [TA] , ligamentum ventriculare, ventricular l..
vocal l. [TA] the band that extends on either side from the thyroid cartilage to the vocal process of the arytenoid cartilage; it is the thickened, free upper border of the conus elasticus of the larynx. SYN: ligamentum vocale [TA] .
volar carpal l. SYN: flexor retinaculum.
Weitbrecht l. SYN: oblique cord of interosseous membrane of forearm.
Winslow l. SYN: fibular collateral l..
Wrisberg l. SYN: posterior meniscofemoral l..
yellow l. SYN: ligamenta flava, under ligamentum.
Y-shaped l. SYN: iliofemoral l..
Zaglas l. a short thick fibrous band extending from the posterior superior spine of the ilium to the second transverse tubercle of the sacrum.
Zinn l. SYN: common tendinous ring of extraocular muscles.

ligamenta
ligamenta (lig′a-men′ta)

Plural of ligamentum. [L.]

ligamentopexis
ligamentopexis, ligamentopexy (lig′a-men-to-pek′sis, -pek′se)

Shortening of any ligament of the uterus. [ligament + G. pexis, fixation]

ligamentous
ligamentous (lig′a-men′tus)

Relating to or of the form or structure of a ligament.

ligamentum
ligamentum, pl .ligamenta (lig′a-men′tum, -men′ta) [TA]

SYN: ligament. [L. a band, tie, fr. ligo, to bind]
l. acromioclaviculare [TA] SYN: acromioclavicular ligament.
l. anococcygeum SYN: anococcygeal ligament.
l. anulare [TA] SYN: anular ligament.
l. anulare bulbi SYN: trabecular tissue of sclera.
l. anulare digitorum SYN: anular part of fibrous digital sheath of digits of hand and foot.
l. anulare radii [TA] SYN: anular ligament of radius.
l. anulare stapedis [TA] SYN: anular ligament of stapes.
ligamenta anularia trachealia [TA] SYN: anular ligaments of trachea, under ligament.
l. apicis dentis SYN: apical ligament of dens.
l. arcuatum laterale [TA] SYN: lateral arcuate ligament.
l. arcuatum mediale [TA] SYN: medial arcuate ligament.
l. arcuatum medianum [TA] SYN: median arcuate ligament.
l. arcuatum pubis SYN: inferior pubic ligament.
l. arteriosum [TA] fibrous remnant of the ductus arteriosus extending between the aortic arch and the pulmonary trunk. SYN: arterial ligament, Botallo ligament.
ligamenta auricularia [TA] SYN: ligaments of auricle, under ligament.
l. bifurcatum [TA] SYN: bifurcate ligament.
l. calcaneocuboideum [TA] SYN: calcaneocuboid ligament.
l. calcaneocuboideum plantare [TA] SYN: plantar calcaneocuboid ligament.
l. calcaneofibulare [TA] SYN: calcaneofibular ligament.
l. calcaneonaviculare [TA] SYN: calcaneonavicular ligament.
l. calcaneonaviculare plantare [TA] SYN: plantar calcaneonavicular ligament.
l. calcaneotibiale SYN: tibiocalcaneal part of medial ligament of ankle joint. SEE ALSO: medial ligament of ankle joint.
l. capitis costae intraarticulare SYN: intraarticular ligament of head of rib.
l. capitis costae radiatum [TA] SYN: radiate ligament of head of rib.
l. capitis femoris [TA] SYN: ligament of head of femur.
l. capitis fibulae anterius [TA] SYN: anterior ligament of fibular head.
l. capitis fibulae posterius [TA] SYN: posterior ligament of fibular head.
ligamenta capitulorum transversa deep transverse metacarpal ligament, deep transverse metatarsal ligament.
l. capsulare [TA] SYN: capsular ligament.
l. cardinale [TA] SYN: cardinal ligament.
l. carpi dorsale SYN: extensor retinaculum.
l. carpi radiatum [TA] SYN: radiate carpal ligament.
l. carpi transversum SYN: flexor retinaculum.
l. carpi volare SYN: flexor retinaculum.
ligamenta carpometacarpalia dorsalia [TA] SYN: dorsal carpometacarpal ligaments, under ligament.
ligamenta carpometacarpalia (dorsalia/palmaria) [TA] SYN: carpometacarpal ligaments (dorsal and palmar), under ligament.
ligamenta carpometacarpalia palmaria [TA] SYN: palmar carpometacarpal ligaments, under ligament.
l. caudale SYN: retinaculum caudale.
l. ceratocricoideum [TA] SYN: ceratocricoid ligament.
l. collaterale, pl .ligamenta collateralia [TA] SYN: collateral ligament.
l. collaterale carpi radiale articulationis radiocarpalis [TA] SYN: radial collateral ligament of wrist joint.
l. collaterale carpi ulnare [TA]
l. collaterale carpi ulnare articulationis radiocarpalis SYN: ulnar collateral ligament of wrist joint.
l. collaterale fibulare [TA] SYN: fibular collateral ligament.
l. collaterale laterale [TA] SYN: lateral ligament of ankle.
l. collaterale mediale [TA] SYN: medial ligament of ankle joint.
l. collaterale radiale articulationis cubiti [TA] SYN: radial collateral ligament of elbow joint.
l. collaterale tibiale [TA] SYN: tibial collateral ligament.
l. collaterale ulnare articulationis cubiti [TA] SYN: ulnar collateral ligament of elbow joint.
l. colli costae SYN: costotransverse ligament.
l. conoideum [TA] SYN: conoid ligament.
l. coracoacromiale [TA] SYN: coracoacromial ligament.
l. coracoclaviculare [TA] SYN: coracoclavicular ligament.
l. coracohumerale [TA] SYN: coracohumeral ligament.
l. corniculopharyngeum SYN: cricopharyngeal ligament.
l. coronarium hepatis [TA] SYN: coronary ligament of liver.
l. costoclaviculare [TA] SYN: costoclavicular ligament.
l. costotransversarium [TA] SYN: costotransverse ligament.
l. costotransversarium anterius SYN: superior costotransverse ligament.
l. costotransversarium laterale [TA] SYN: lateral costotransverse ligament.
l. costotransversarium posterius SYN: lateral costotransverse ligament.
l. costotransversarium superius [TA] SYN: superior costotransverse ligament.
l. costoxiphoideum [TA] SYN: costoxiphoid ligament.
l. cotyloideum SYN: acetabular labrum.
l. cricoarytenoideum posterius SYN: cricoarytenoid ligament.
l. cricopharyngeum [TA] SYN: cricopharyngeal ligament.
l. cricotracheale [TA] SYN: cricotracheal ligament.
ligamenta cruciata digitorum SYN: cruciform part of fibrous digital sheath.
ligamenta cruciata genus SYN: cruciate ligaments of knee, under ligament.
l. cruciatum anterius SYN: anterior cruciate ligament.
l. cruciatum atlantis SYN: cruciate ligament of the atlas.
l. cruciatum cruris SYN: inferior extensor retinaculum.
l. cruciatum posterius [TA] SYN: posterior cruciate ligament.
l. cruciatum tertium genus SYN: posterior meniscofemoral ligament.
l. cruciforme atlantis [TA] SYN: cruciate ligament of the atlas.
ligamenta cuboideonaviculare [TA] SYN: cuboideonavicular ligaments, under ligament.
l. cuboideonaviculare dorsale [TA] SYN: dorsal cuboideonavicular ligament.
ligamenta cuboideonavicularia plantaria [TA] SYN: plantar cuboideonavicular ligaments, under ligament.
l. cuneocuboideum [TA] SYN: cuneocuboid ligaments, under ligament.
l. cuneocuboideum dorsale [TA] SYN: dorsal cuneocuboid ligament.
l. cuneocuboideum interosseum SYN: cuneocuboid interosseous ligament.
l. cuneocuboideum plantare [TA] SYN: plantar cuneocuboid ligament.
ligamenta cuneometatarsalia interossea [TA] SYN: cuneometatarsal interosseous ligaments, under ligament.
ligamenta cuneonavicularia dorsalia [TA] SYN: dorsal cuneonavicular ligaments, under ligament.
ligamenta cuneonavicularia plantaria [TA] SYN: plantar cuneonavicular ligaments, under ligament.
l. deltoideum medial ligament of ankle joint.
l. denticulatum [TA] SYN: denticulate ligament.
l. ductus venosi SYN: l. venosum.
l. duodenorenale SYN: duodenorenal ligament.
ligamenta epididymidis (inferius et superius) [TA] SYN: ligaments of epididymis (inferior and superior), under ligament.
l. epididymidis inferius [TA] SYN: inferior ligament of epididymis.
l. epididymidis superius [TA] SYN: superior ligament of epididymis.
ligamenta extracapsularia [TA] SYN: extracapsular ligaments, under ligament.
l. falciforme SYN: falciform process of sacrotuberous ligament.
l. falciforme hepatis [TA] SYN: falciform ligament of liver.
ligamenta flava [TA] paired ligaments of yellow elastic fibrous tissue, which bind together the laminae of adjoining vertebrae, forming the dorsal wall of the vertebral canal between the vertebra or laminae; penetration of the l. flavum with a trocar during epidural or spinal puncture produces a distinct feel (“pop”), letting the practitioner know that the tip of the trocar has entered the epidural space. SYN: yellow ligament.
l. fundiforme clitoridis [TA] SYN: fundiform ligament of clitoris.
l. fundiforme penis [TA] SYN: fundiform ligament of penis.
l. gastrocolicum [TA] SYN: gastrocolic ligament.
l. gastrolienale gastrosplenic ligament.
l. gastrophrenicum [TA] SYN: gastrophrenic ligament.
l. gastrosplenicum [TA] SYN: gastrosplenic ligament.
l. genitoinguinale SYN: genitoinguinal ligament.
ligamenta glenohumeralia [TA] SYN: glenohumeral ligaments, under ligament.
l. glenoidale SYN: glenoid labrum of scapula.
l. hepatocolicum [TA] SYN: hepatocolic ligament.
l. hepatoduodenale [TA] SYN: hepatoduodenal ligament.
l. hepatoesophageum [TA] SYN: hepatoesophageal ligament.
l. hepatogastricum [TA] SYN: hepatogastric ligament.
l. hepatorenale [TA] SYN: hepatorenal ligament.
l. hyaloideo-capsulare SYN: hyalocapsular ligament.
l. hyoepiglotticum [TA] SYN: hyoepiglottic ligament.
l. hyothyroideum laterale SYN: lateral thyrohyoid ligament.
l. hyothyroideum medium SYN: median thyrohyoid ligament.
l. iliofemorale [TA] SYN: iliofemoral ligament.
l. iliolumbale [TA] SYN: iliolumbar ligament.
l. iliopectineale SYN: iliopectineal arch.
l. incudis posterius [TA] SYN: posterior ligament of incus.
l. incudis superius [TA] SYN: superior ligament of incus.
l. inguinale [TA] SYN: inguinal ligament.
ligamenta intercarpalia [TA] SYN: intercarpal ligaments, under ligament.
l. intercarpalia dorsalia dorsal intercarpal ligament. See intercarpal ligaments, under ligament.
l. intercarpalia interossea interosseous intercarpal ligament. See intercarpal ligaments, under ligament.
l. intercarpalia palmaria palmar intercarpal ligament. See intercarpal ligaments, under ligament.
l. interclaviculare [TA] SYN: interclavicular ligament.
ligamenta intercostalia SYN: intercostal membranes, under membrane.
ligamenta intercuneiformia [TA] SYN: intercuneiform ligaments, under ligament.
ligamenta intercuneiformia dorsalia dorsal intercuneiform ligament. See intercuneiform ligaments, under ligament.
ligamenta intercuneiformia interossea interosseous intercuneiform ligaments. See intercuneiform ligaments, under ligament.
ligamenta intercuneiformia plantaria plantar intercuneiform ligaments. See intercuneiform ligaments, under ligament.
l. interfoveolare [TA] SYN: interfoveolar ligament.
l. interspinale [TA] SYN: interspinous ligament.
l. intertransversarium [TA] SYN: intertransverse ligament.
ligamenta intracapsularia [TA] SYN: intracapsular ligaments, under ligament.
l. ischiocapsulare SYN: ischiofemoral ligament.
l. ischiofemorale [TA] SYN: ischiofemoral ligament.
l. jugale SYN: cricopharyngeal ligament.
l. laciniatum SYN: flexor retinaculum of lower limb.
l. lacunare [TA] SYN: lacunar ligament.
l. laterale articulationis temporomandibularis [TA] SYN: lateral ligament of temporomandibular joint.
l. laterale vesicae [TA] SYN: lateral ligament of bladder.
l. latum pulmonis SYN: pulmonary ligament.
l. latum uteri [TA] SYN: broad ligament of the uterus.
l. lienorenale splenorenal ligament.
l. longitudinale anterius [TA] SYN: anterior longitudinal ligament.
l. longitudinale posterius [TA] SYN: posterior longitudinal ligament.
ligamenta longitudinalia SYN: longitudinal ligaments, under ligament.
l. lumbocostale [TA] SYN: lumbocostal ligament.
l. mallei anterius [TA] SYN: anterior ligament of malleus.
l. mallei laterale [TA] SYN: lateral ligament of malleus.
l. mallei superius [TA] SYN: superior ligament of malleus.
l. malleoli lateralis anterior tibiofibular ligament, posterior tibiofibular ligament.
l. mediale SYN: anterior tibiotalar part of medial ligament of ankle joint.
l. mediale articulationis talocruralis SYN: medial ligament of ankle joint.
l. mediale articulationis temporomandibularis [TA] SYN: medial ligament of temporomandibular joint.
l. mediale puboprostaticum pubovesical ligament (of male).
l. menisci lateralis SYN: posterior meniscofemoral ligament.
ligamenta meniscofemoralia [TA] SYN: meniscofemoral ligaments, under ligament.
l. meniscofemorale anterius [TA] SYN: anterior meniscofemoral ligament.
l. meniscofemorale posterius [TA] SYN: posterior meniscofemoral ligament.
l. metacarpale transversum profundum [TA] SYN: deep transverse metacarpal ligament.
l. metacarpale transversum superficiale [TA] SYN: superficial transverse metacarpal ligament.
ligamenta metacarpalia dorsalia [TA] SYN: dorsal metacarpal ligaments, under ligament.
ligamenta metacarpalia interossea [TA] SYN: interosseous metacarpal ligaments, under ligament.
ligamenta metacarpalia palmaria [TA] SYN: palmar metacarpal ligaments, under ligament.
l. metatarsale transversum profundum [TA] SYN: deep transverse metatarsal ligament.
l. metatarsale transversum superficiale [TA] SYN: superficial transverse metatarsal ligament.
ligamenta metatarsalia dorsalia [TA] SYN: dorsal metatarsal ligaments, under ligament.
ligamenta metatarsalia interossea [TA] SYN: metatarsal interosseous ligaments, under ligament.
ligamenta metatarsalia plantaria [TA] SYN: plantar metatarsal ligaments, under ligament.
l. natatorium SYN: superficial transverse metacarpal ligament.
ligamenta navicularicuneiformia dorsal cuneonavicular ligaments, under ligament, plantar cuneonavicular ligaments, under ligament.
l. nuchae [TA] a sagittal ligamentous band at the back of the neck, formed of thickened supraspinous ligaments; it extends from the external occipital protuberance to the posterior border of the foramen magnum cranially and to the seventh cervical spinous process caudally. SYN: nuchal ligament&star, apparatus ligamentosus colli.
l. orbiculare radii SYN: anular ligament of radius.
ligamenta ossiculorum auditorium ligaments of auditory ossicles, under ligament.
ligamenta ossiculorum auditus [TA] SYN: ligaments of auditory ossicles, under ligament.
l. ovarii proprium [TA] SYN: ligament of ovary.
ligamenta palmaria [TA] SYN: palmar ligaments, under ligament.
ligamenta palmaria articulationis interphalangeae manus [TA] SYN: palmar ligaments of interphalangeal joints of hand, under ligament.
ligamenta palmaria articulationis metacarpophalangeae [TA] SYN: palmar ligaments of metacarpophalangeal joints, under ligament.
l. palpebrale externum SYN: lateral palpebral ligament.
l. palpebrale laterale [TA] SYN: lateral palpebral ligament.
l. palpebrale mediale [TA] SYN: medial palpebral ligament.
l. patellae [TA] SYN: patellar ligament.
l. pectinatum pectinate ligaments of iridocorneal angle. See trabecular tissue of sclera.
l. pectinatum anguli iridocornealis pectinate ligaments of iridocorneal angle. See trabecular tissue of sclera.
l. pectinatum iridis pectinate ligaments of iridocorneal angle. See trabecular tissue of sclera.
l. pectineale [TA] SYN: pectineal ligament.
l. phrenicocolicum [TA] SYN: phrenicocolic ligament.
l. phrenicolienale SYN: phrenicosplenic ligament.
l. phrenicosplenicum [TA] SYN: phrenicosplenic ligament.
l. pisohamatum [TA] SYN: pisohamate ligament.
l. pisometacarpeum [TA] SYN: pisometacarpal ligament.
l. plantare longum [TA] SYN: long plantar ligament.
ligamenta plantaria [TA] SYN: plantar ligaments, under ligament.
ligamenta plantaria articulationis interphalangeae pedis [TA] SYN: plantar ligaments of interphalangeal joints of foot, under ligament.
ligamenta plantaria articulationis metatarsophalangeae [TA] SYN: plantar ligaments of metatarsophalangeal joints, under ligament.
l. popliteum arcuatum [TA] SYN: arcuate popliteal ligament.
l. popliteum obliquum [TA] SYN: oblique popliteal ligament.
l. pterygospinale [TA] SYN: pterygospinous ligament.
l. pubicum inferius [TA] SYN: inferior pubic ligament.
l. pubicum superius [TA] SYN: superior pubic ligament.
l. pubocapsulare SYN: pubofemoral ligament.
l. pubofemorale [TA] SYN: pubofemoral ligament.
l. puboprostaticum [TA] SYN: puboprostatic ligament.
l. puboprostaticum laterale See puboprostatic ligament.
l. puboprostaticum mediale See puboprostatic ligament.
l. pubovesicale (femininum) [TA] SYN: pubovesical ligament (of female).
l. pubovesicale (masculinum) [TA] SYN: pubovesical ligament (of male).
l. pulmonale [TA] SYN: pulmonary ligament.
l. quadratum [TA] SYN: quadrate ligament.
l. radiatum SYN: radiate ligament of head of rib.
l. radiocarpale dorsale [TA] SYN: dorsal radiocarpal ligament.
l. radiocarpale palmare [TA] SYN: palmar radiocarpal ligament.
l. reflexum [TA] SYN: reflected inguinal ligament.
l. sacrococcygeum anterius [TA] SYN: anterior sacrococcygeal ligament.
l. sacrococcygeum dorsale superficiale superficial posterior sacrococcygeal ligament.
l. sacrococcygeum laterale [TA] SYN: lateral sacrococcygeal ligament.
l. sacrococcygeum posterius profundum SYN: deep posterior sacrococcygeal ligament.
l. sacrococcygeum posterius superficiale [TA] SYN: superficial posterior sacrococcygeal ligament.
l. sacrodurale SYN: sacrodural ligament.
ligamenta sacroiliaca anteriora [TA] SYN: anterior sacroiliac ligaments, under ligament.
ligamenta sacroiliaca interossea [TA] SYN: interosseous sacroiliac ligaments, under ligament.
ligamenta sacroiliaca posteriora [TA] SYN: posterior sacroiliac ligaments, under ligament.
l. sacroiliacum posterius SYN: posterior sacroiliac ligaments, under ligament.
l. sacrospinale [TA] SYN: sacrospinous ligament.
l. sacrospinosum SYN: sacrospinous ligament.
l. sacrotuberale [TA] SYN: sacrotuberous ligament.
l. sacrotuberosum SYN: sacrotuberous ligament.
l. serosum SYN: serous ligament.
l. sphenomandibulare [TA] SYN: sphenomandibular ligament.
l. spirale cochleae SYN: spiral ligament of cochlear duct, spiral ligament of cochlear duct.
l. spirale ductus cochlearis [TA] SYN: spiral ligament of cochlear duct.
l. splenorenale [TA] SYN: splenorenal ligament.
ligamenta sternoclavicularia SYN: sternoclavicular ligaments, under ligament.
l. sternoclaviculare anterius [TA] SYN: anterior sternoclavicular ligament.
l. sternoclaviculare posterius [TA] SYN: posterior sternoclavicular ligament.
l. sternocostale intraarticulare [TA] SYN: intraarticular sternocostal ligament.
ligamenta sternocostalia radiata [TA] SYN: radiate sternocostal ligaments, under ligament.
ligamenta sternopericardiaca [TA] SYN: sternopericardial ligaments, under ligament.
l. stylohyoideum [TA] SYN: stylohyoid ligament.
l. stylomandibulare [TA] SYN: stylomandibular ligament.
l. supraspinale [TA] SYN: supraspinous ligament.
ligamenta suspensoria mammaria SYN: suspensory ligaments of breast, under ligament.
l. suspensorium axillae [TA] SYN: suspensory ligament of axilla.
l. suspensorium bulbi [TA] SYN: suspensory ligament of eyeball.
l. suspensorium clitoridis [TA] SYN: suspensory ligament of clitoris.
l. suspensorium duodeni suspensory muscle of duodenum.
l. suspensorium glandulae thyroideae [TA] SYN: suspensory ligament of thyroid gland.
l. suspensorium ovarii [TA] SYN: suspensory ligament of ovary.
l. suspensorium penis [TA] SYN: suspensory ligament of penis.
l. talocalcaneum [TA] SYN: talocalcaneal ligament.
l. talocalcaneare interosseum SYN: talocalcaneal interosseous ligament.
l. talocalcaneum laterale [TA] SYN: lateral talocalcaneal ligament.
l. talocalcaneum mediale [TA] SYN: medial talocalcaneal ligament.
l. talocalcaneum posterius [TA] SYN: posterior talocalcaneal ligament.
l. talofibulare anterius [TA] SYN: anterior talofibular ligament.
l. talofibulare posterius [TA] SYN: posterior talofibular ligament.
l. talonaviculare [TA] SYN: talonavicular ligament.
l. talotibiale anterius SYN: anterior tibiotalar part of medial ligament of ankle joint. SEE ALSO: medial ligament of ankle joint.
l. talotibiale posterius SYN: tibiotalar part of medial ligament of ankle joint. SEE ALSO: medial ligament of ankle joint.
l. tarsale externum SYN: lateral palpebral ligament.
l. tarsale internum SYN: medial palpebral ligament.
ligamenta tarsi [TA] SYN: tarsal ligaments, under ligament.
ligamenta tarsi dorsalia [TA] SYN: dorsal tarsal ligaments, under ligament.
ligamenta tarsi interossea [TA] SYN: tarsal interosseous ligaments, under ligament.
ligamenta tarsi plantaria [TA] SYN: plantar tarsal ligaments, under ligament.
ligamenta tarsometatarsalia [TA] SYN: tarsometatarsal ligaments, under ligament.
ligamenta tarsometatarsalia dorsalia [TA] SYN: dorsal tarsometatarsal ligaments, under ligament.
ligamenta tarsometatarsalia plantaria [TA] SYN: plantar tarsometatarsal ligaments, under ligament.
l. temporomandibulare SYN: lateral ligament of temporomandibular joint.
l. teres femoris SYN: ligament of head of femur.
l. teres hepatis [TA] SYN: round ligament of liver.
l. teres uteri [TA] SYN: round ligament of uterus.
l. testis the caudal portion of the embryonic urogenital ridge; the upper third of the gubernaculum testis.
l. thyroepiglotticum [TA] SYN: thyroepiglottic ligament.
l. thyrohyoideum laterale [TA] SYN: lateral thyrohyoid ligament.
l. thyrohyoideum medianum [TA] SYN: median thyrohyoid ligament.
l. tibiofibulare anterius [TA] SYN: anterior tibiofibular ligament.
l. tibiofibulare medium SYN: interosseous membrane of leg.
l. tibiofibulare posterius [TA] SYN: posterior tibiofibular ligament.
l. tibionaviculare SYN: tibionavicular part of medial ligament of ankle joint.
ligamenta trachealia SYN: anular ligaments of trachea, under ligament.
l. transversale cervicis SYN: cardinal ligament.
l. transversum acetabuli [TA] SYN: transverse acetabular ligament.
l. transversum atlantis [TA] SYN: transverse ligament of the atlas.
l. transversum cruris SYN: superior extensor retinaculum.
l. transversum genus [TA] SYN: transverse ligament of knee.
l. transversum humeri [TA] SYN: transverse humeral ligament.
l. transversum pelvis SYN: transverse perineal ligament.
l. transversum perinei [TA] SYN: transverse perineal ligament.
l. transversum scapulae inferius [TA] SYN: inferior transverse scapular ligament.
l. transversum scapulae superius [TA] SYN: superior transverse scapular ligament.
l. trapezoideum [TA] SYN: trapezoid ligament.
l. triangulare SYN: perineal membrane.
l. triangulare dextrum hepatis [TA] SYN: right triangular ligament of liver.
l. triangulare sinistrum hepatis [TA] SYN: left triangular ligament of liver.
l. tuberculi costae SYN: lateral costotransverse ligament.
l. ulnocarpale palmare [TA] SYN: palmar ulnocarpal ligament.
l. umbilicale laterale an old name for l. umbilicale mediale. SYN: lateral umbilical ligament.
l. umbilicale mediale SYN: cord of umbilical artery.
l. umbilicale medianum [TA] SYN: median umbilical ligament.
l. uteroovaricum ligament of ovary.
l. venae cavae sinistrae [TA] SYN: ligament of left vena cava.
l. venosum [TA] a thin fibrous cord, lying in the fissure of the l. venosum, the remains of the ductus venosus of the fetus. SYN: Arantius ligament, l. ductus venosi, venous ligament.
l. ventriculare SYN: vestibular ligament.
l. vestibulare [TA] SYN: vestibular ligament.
l. vocale [TA] SYN: vocal ligament.

ligand
ligand (lig′and, li′gand)

1. Any individual atom, group, or molecule attached to a central metal ion by multiple coordinate bonds; e.g., the porphyrin portion of heme, the corrin nucleus of the B₁₂ vitamins. 2. An organic molecule attached to a tracer element, e.g., a radioisotope. 3. A molecule that binds to a macromolecule, e.g., a l. binding to a receptor. 4. The analyte in competitive binding assays, such as radioimmunoassay. 5. An atom or group covalently attached to a specified carbon atom in an organic molecule. [L. ligo, to bind]
addressin ligands ligands on cells for specific homing receptors on lymphocytes.
Fas l. a molecule on the surface of cytotoxic T cells that binds to its receptor, Fas, on the surface of other cells, initiating apoptosis in the target cell.

ligandin
ligandin (li-gan′din)

SYN: glutathione S-transferase.

ligase
ligase (li′gas)

Generic term for enzymes (EC class 6) catalyzing the joining of two molecules coupled with the breakdown of a pyrophosphate bond in ATP or a similar compound. SEE ALSO: synthetase.

ligate
ligate (li′gat)

To apply a ligature. [L. ligo, pp. -atus, to bind]

ligation
ligation (li-ga′shun)

1. Application of a ligature. 2. The act of binding or annealing. [L. ligatio, fr. ligo, to bind]
blunt-end l. a reaction that joins two DNA duplexes directly at their blunt ends.
enzyme-catalyzed l. an enzyme-mediated joining of phosphodiester linkage of two stretches of DNA or RNA, or of peptide linkage of two polypeptides.
pole l. a l. at the root of an organ to shut off or diminish blood supply.
surgical l. in dentistry, the surgical exposure of an unerupted tooth so that a metal ligature can be placed around its cervix and fastened to an orthodontic appliance to facilitate eruption.
tooth l. the binding together of teeth with wire for stabilization and immobilization following traumatic injury or orthognathic surgery, or during periodontal therapy.
tubal l. interruption of the continuity of the oviducts by cutting, cautery, or by a plastic or metal device to prevent future conception.

ligator
ligator (li′ga-ter, -tor)

An instrument used in the ligation of vessels in deep and nearly inaccessible parts.

ligature
ligature (lig′a-choor)

1. A thread, wire, fillet, or the like, tied tightly around a blood vessel, the pedicle of a tumor, or other structure to constrict it. 2. In orthodontics, a wire or other material used to secure an orthodontic attachment or tooth to an archwire. [L. ligatura, a band or tie, fr. ligo, to tie]
elastic l. 1. a rubber l. that slowly constricts; 2. in orthodontics, a stretchable threadlike material that may be tied from a tooth to an archwire or from tooth to tooth to gain movement of these units.
intravascular l. balloon occlusion of the feeding vessels of a cerebral arteriovenous malformation.
nonabsorbable l. a permanent l. of inert material, such as silk, wire, or synthetic fiber, that does not undergo dissolution in human tissues.
occluding l. a l. to shut off completely the distal blood supply.
provisional l. a l. applied to an artery in continuity at the beginning of an operation to prevent hemorrhage, but removed when the operation is completed.
soluble l. a temporary l. of material that can be absorbed by human tissues.
Stannius l. a l. placed either around the junction between the sinus venosus and atrium of the frog or turtle heart (first Stannius l.) or around the atrioventricular junction (second Stannius l.); demonstrates that the cardiac impulse is conducted from sinus venosus to atria to ventricle, but that successive chambers possess automaticity since each may continue to beat, but the atria now have a slower rate than the sinus venosus, and the ventricle either does not contract or beats at a slower rate than the atria.
suboccluding l. a l. to diminish blood supply and encourage collateral circulation.
suture l. a l. applied by passing a needle with attached thread through or around a structure to more firmly secure the l..

light
light (lit)

That portion of electromagnetic radiation (between 390 and 770 nm) to which the retina is sensitive (wavelength range of 380–780 nm). SEE ALSO: lamp. [A.S. leoht]
cold l. 1. SYN: bioluminescence (1) . 2. fluorescent l. as opposed to incandescent l..
infrared l. infrared.
invisible l. historic term for x-rays.
minimum l. visual threshold.
polarized l. l. in which, as a result of reflection or transmission through certain media, the vibrations are all in one plane, transverse to the ray, instead of in all planes.
reflected l. l. directed backward from a mirror.
refracted l. bent rays of l. changed in passage from one transparent medium to another of unequal density. SEE ALSO: refraction.
transmitted l. l. passed through a transparent medium.
Wood l. ultraviolet l. produced by Wood lamp.

lightening
lightening (lit′en-ing)

Sensation of decreased abdominal distention during the later weeks of pregnancy following the descent of the fetal head into the pelvic inlet.

light green SF yellowish
light green SF yellowish [C.I. 42095]

An acid arylmethane dye, used as a cytoplasmic stain in plant and animal histology; fades badly in bright light.

ligneous
ligneous (lig′ne-us)

Woody; having a woody feeling. [L. ligneus, wooden, fr. lignum, wood]

lignin
lignin (lig′nin)

A random polymer of coniferyl alcohol accompanying cellulose and present in vegetable fiber and wood cells; a source of vanillin (by oxidation of l.); l. composition varies with plant species. It is one of the most abundant biopolymers in nature. [L. lignum, wood]

lignoceric acid
lignoceric acid (lig-no-sar′ik, -ser′ik)

An acid present in one type of sphingolipid and in small amounts in triacylglycerols. SYN: n-tetracosanoic acid.

likelihood
likelihood

A statement of the chance that an unknown quantity in reality has a particular value based on the readiness with which it would account for a given set of data; in this way the merits of various competing interpretations may be compared.

Likert
Likert

Rensis, U.S. social psychologist, *1903. See L. scale.

Lillie
Lillie

Ralph D., U.S. pathologist, 1896–1979. See Glenner-L. stain for pituitary. See entries under stain.

Lilly
Lilly

John C., U.S. physiologist, *1915. See Silverman-L. pneumotachograph.

limb
limb (lim) [TA]

1. An extremity; a member; an arm or leg. SYN: member. 2. A segment of any jointed structure. SEE ALSO: leg, crus. [A.S. lim]
ampullary membranous limbs of semicircular ducts [TA] the dilated ends of the three semicircular ducts, each of which contains a specialized thickening of the epithelium known as the ampullary crest. SYN: crura membranacea ampullaria ductuum semicircularium [TA] , ampullary crura of semicircular ducts.
anacrotic l. the ascending l. of an arterial pulse tracing.
anterior l. of internal capsule [TA] the portion of the internal capsule between the head of the caudate nucleus and the putamen; it lies anterior to the genu of the internal capsule. SYN: crus anterius capsulae internae [TA] .
anterior l. of stapes [TA] the anterior of the two delicate curving limbs of the stapes that pass from the head of the bone to the base or footplate. SYN: crus anterius stapedis [TA] , anterior crus of stapes.
limbs of bony semicircular canals SYN: bony limbs of semicircular canals.
bony limbs of semicircular canals [TA] the extremities of the bony semicircular canals in which the corresponding membranous limbs of the semicircular ducts are located; they are the common bony limbs (crus osseum commune), simple bony limbs (crus osseum simplex), and ampullary bony limbs (crus ossea ampullaria). SYN: crura of bony semicircular canals, crura ossea canalium semicircularium, limbs of bony semicircular canals.
common membranous l. of membranous semicircular ducts SYN: common membranous l. of semicircular ducts.
common membranous l. of semicircular ducts [TA] the united, nonampullary ends of the superior and posterior semicircular ducts. SYN: crus membranaceum commune ductuum semicircularium [TA] , common crus of semicircular ducts, common membranous l. of membranous semicircular ducts.
l. of helix SYN: crus of helix.
inferior l. SYN: lower l..
inferior l. of ansa cervicalis inferior root of ansa cervicalis.
lateral l. SYN: lateral crus.
long l. of incus [TA] the process of the incus that articulates with the stapes. SYN: crus longum incudis [TA] , long crus of incus.
lower l. [TA] the hip, thigh, leg, ankle, and foot. SYN: inferior member [TA] , membrum inferius [TA] , inferior l., lower extremity, pelvic l..
medial l. SYN: medial crus.
pelvic l. SYN: lower l..
phantom l. SYN: phantom l. pain.
posterior l. of internal capsule [TA] that subdivision of the internal capsule caudal to the genu and located between the thalamus and lentiform nucleus. SYN: crus posterius capsulae internae [TA] .
posterior l. of stapes [TA] the posterior of the two delicate limbs of the stapes that connect the head and base or footplate of the bone. SYN: crus posterius stapedis [TA] , posterior crus of stapes.
retrolenticular l. of internal capsule retrolentiform l. of internal capsule.
retrolentiform l. of internal capsule [TA] the portion of the internal capsule located caudal to the posterior l. of the internal capsule and the lenticular (lentiform) nucleus. SEE ALSO: retrolenticular part of internal capsule. SYN: pars retrolentiformis cruris posterior [TA] , retrolenticular l. of internal capsule&star.
short l. of incus [TA] the short crus of incus; the process of the incus that fits into a depression (fossa incudis) in the epitympanic recess. SYN: crus breve incudis [TA] , short crus of incus.
simple membranous l. of semicircular duct [TA] the non-ampullary end of the lateral semicircular duct that opens independently into the utricle. SYN: crus membranaceum simplex ductus semicircularis [TA] , simple crus of semicircular duct.
sublenticular l. of internal capsule sublentiform l. of internal capsule.
sublentiform l. of internal capsule [TA] the portion of the internal capsule located ventral to caudal portions of the lenticular nucleus. SEE ALSO: sublenticular part of internal capsule. SYN: pars sublentiformis cruris posterioris [TA] , sublenticular l. of internal capsule&star.
superior l. SYN: upper l..
superior l. of ansa cervicalis superior root of ansa cervicalis.
thoracic l. SYN: upper l..
upper l. [TA] the shoulder, arm, forearm, wrist, and hand. SYN: membrum superius [TA] , superior member [TA] , superior l., thoracic l., upper extremity.

limbic
limbic (lim′bik)

1. Relating to a limbus. 2. Relating to the l. system.

limbus
limbus, pl .limbi (lim′bus, lim′bi)

The edge, border, or fringe of a part. [L. a border]
l. acetabuli [TA] SYN: acetabular margin.
l. alveolaris 1. SYN: alveolar arch of mandible. 2. SYN: alveolar arch of maxilla.
l. anterior palpebrae [TA] SYN: anterior palpebral margin.
l. of cornea SYN: corneal l..
l. corneae SYN: corneal l..
corneal l. [TA] the margin of the cornea overlapped by the sclera. SYN: corneal margin, corneoscleral junction, l. corneae, l. of cornea, sclerocorneal junction.
l. fossae ovalis [TA] a muscular ring surrounding the fossa ovalis in the wall of the right atrium of the heart. SYN: anulus ovalis, margin of fossa ovalis, Vieussens anulus, Vieussens isthmus, Vieussens l., Vieussens ring.
l. laminae spiralis osseae [TA] SYN: l. of osseous spiral lamina.
l. membranae tympani SYN: l. of tympanic membrane.
l. of osseous spiral lamina [TA] the border of the spiral lamina; the thickened periosteum covering the upper plate of the bony spiral lamina of the cochlea. SYN: l. laminae spiralis osseae [TA] .
limbi palpebrales [TA] SYN: palpebral margins, under margin.
l. penicillatus SYN: brush border.
l. posterior palpebrae [TA]
l. sphenoidalis [TA] SYN: l. of sphenoid (bone).
l. of sphenoid (bone) [TA] variably prominent ridge on the body of the sphenoid (bone) forming the posterior border of the jugum sphenoidale and the anterior border of the prechiasmatic sulcus. SYN: l. sphenoidalis [TA] .
l. striatus SYN: striated border.
l. of tympanic membrane margin of the tympanic membrane attaching to the tympanic sulcus. SYN: l. membranae tympani.
Vieussens l. SYN: l. fossae ovalis.

lime
lime (lim)

1. CaO;an alkaline earth oxide occurring in grayish white masses (quicklime); on exposure to the atmosphere it becomes converted into calcium hydrate and calcium carbonate (air-slaked l.); direct addition of water to calcium oxide produces calcium hydrate (slaked l.). SYN: calcium oxide, calx (1) . 2. Fruit of the l. tree, Citrus medica (family Rutaceae), which is a source of ascorbic acid and acts as an antiscorbutic agent. [O.E. lim, birdlime]
air-slaked l. l. (1) .
chlorinated l. a mixture of varying proportions of complexes of chlorine with calcium oxide and calcium hydroxide. Contains 24–37% available chlorine. Decomposes in moist conditions to liberate chlorine. Strong irritant due to chlorine vapors. Used for disinfecting drinking water, sewage etc.; in the bleaching of wood pulp, linen, cotton, straw, oils, soaps, and laundry; as an oxidizer; in destroying caterpillars; and as a decontaminant for mustard gas and similar substances. SYN: bleaching powder.
slaked l. l. (1) .
sulfurated l. SYN: crude calcium sulfide.

limen
limen, pl .limina (li′men, lim′i-na) [TA]

1. Entrance; the external opening of a canal or space, such as l. insulae [TA]. 2. SYN: threshold. [L.]
difference l. a barely noticeable change in the intensity or frequency of a stimulus.
l. insulae [TA] the band of transition between the anterior portion of the gray matter of the insula and the anterior perforated substance; it is formed by a narrow strip of olfactory cortex along the lateral side of the lateral olfactory stria. SYN: threshold of island of Reil.
l. nasi [TA] a ridge marking the boundary between the nasal cavity proper and the vestibule. SYN: threshold of nose.

limerence
limerence (lim′er-ens)

Emotional excitement of being in love.

limes
limes (L) (li′mez)

A boundary, limit, or threshold. SEE ALSO: L doses, under dose. [L.]

liminal
liminal (lim′i-nal)

1. Pertaining to a threshold. 2. Pertaining to a stimulus just strong enough to excite a tissue, e.g., nerve or muscle. [L. limen (limin-), a threshold]

liminometer
liminometer (lim-i-nom′e-ter)

An instrument for measuring the strength of a stimulus which is barely sufficient to produce a reflex response. [L. limen, threshold, + G. metron, measure]

limit
limit

A boundary or end. [L. limes, boundary]
critical l. the upper or lower boundary of a laboratory test result that indicates a life-threatening value.
elastic l. the greatest stress to which a material may be subjected and still be capable of returning to its original dimensions when the forces are released.
Hayflick l. the l. of human cell division in subcultures; such cells typically divide only about 50 times before dying out.
permissible exposure l. an occupational health standard to safeguard workers against dangerous contaminants in the workplace.
proportional l. the greatest stress that a material is capable of sustaining without any deviation from proportionality of stress to strain (Hooke law).
quantum l. the shortest wavelength found in an x-ray spectrum.
short-term exposure l. (STEL) the maximum concentration of a chemical to which workers may be exposed continuously for up to 15 minutes without danger to health or work efficiency and safety.
tolerance limits specified performance limits for allowable error for a test; the limits selected should depend on both the effect of the error on the clinical significance of a test and on what is technically achievable.

Limnatis nilotica
Limnatis nilotica (lim-na′tis ni-lot′i-ka)

The horse leech; a species of land-leech of southern Europe and northern Africa which may infest the nostrils or gullet and, attaching itself to the mucous membrane, may cause hemorrhages and anemia in horses and other animals drinking leech-infested water. [G. limne, pool]

limnemia
limnemia (lim-ne′me-a)

SYN: chronic malaria. [G. limne, marsh, + haima, blood]

limnemic
limnemic (lim-ne′mik)

Suffering from chronic malaria.

limnology
limnology (lim-nol′o-je)

Study of the physical, chemical, meteorologic, and biologic conditions in fresh water; a branch of ecology. [G. limne, pool, + logos, study]

limon
limon, gen. limonis (li′mon, li-mo′nis)

SYN: lemon. [L.]

limophthisis
limophthisis (li-mof′thi-sis)

Rarely used term for emaciation from lack of sufficient nourishment. [G. limos, hunger, + phthisis, wasting]

limp
limp

A lame walk with a yielding step; asymmetrical gait. SEE ALSO: claudication.

LINAC
LINAC

Acronym of linear accelerator.

lincomycin
lincomycin (lin-ko-mi′sin)

An antibacterial substance, composed of substituted pyrrolidine and octapyranose moities, produced by Streptomyces lincolnensis; active against Gram-positive organisms; used medicinally as l. hydrochloride.

lincture
lincture, linctus (link′choor, link′tus)

An electuary or a confection; originally a medicinal preparation taken by licking. [L. lingo, pp. linctus, to lick]

lindane
lindane (lin′dan)

Used as a scabicide, pediculicide, and insecticide (10 times more toxic for houseflies than DDT).

Lindau
Lindau

Arvid, Swedish pathologist, 1892–1958. See L. disease, L. tumor, von Hippel-L. syndrome.

Lindbergh
Lindbergh

Charles A., U.S. aviator, 1902–1974. See Carrel-L. pump.

Lindner
Lindner

Karl D., Austrian ophthalmologist, 1883–1961. See L. bodies, under body.

Lindqvist
Lindqvist

Johan Torsten, Swedish physician, *1906. See Fahraeus-L. effect.

line
line (lin) [TA]

1. A mark, strip, or streak. In anatomy, a long, narrow mark, strip, or streak distinguished from the adjacent tissues by color, texture, or elevation. SEE ALSO: linea. 2. A unit of measurement used by histologists in the 19th century; it varied in different countries from 110–112 of an English inch. 3. A laboratory derivative of a stock of organisms maintained under defined physical conditions. 4. A section of tubing supplying fluid or conducting impulses for monitoring equipment; e.g., intravenous l., arterial l.. SYN: linea [TA] . [L. linea, a linen thread, a string, l., fr. linum, flax]
absorption lines the dark lines in the solar spectrum due to absorption by the solar and the earth's atmosphere; the phenomenon occurs because rays passing from an incandescent body through a colder medium are absorbed by elements in that medium.
accretion lines lines seen in microscopic sections of the enamel, marking successive layers of added material.
alveolonasal l. a l. connecting the alveolar point and the nasion.
Amberg lateral sinus l. a l. dividing the angle formed by the anterior edge of the mastoid process and the temporal l..
anocutaneous l. [TA] inferior border of the anal pecten where the stratified squamous epithelium changes from the hairless anoderm to typical (hairy) skin; commonly coincides with the inferior border of the internal anal sphincter. SYN: linea anorectalis [TA] .
anterior axillary l. [TA] a vertical l. extending inferiorly from the anterior axillary fold. SYN: linea axillaris anterior [TA] , linea preaxillaris, preaxillary l..
anterior junction l. radiographic projection of the mediastinal tissue septum between the upper lobes behind the sternum.
anterior median l. [TA] the l. of intersection of the midsagittal plane with the anterior surface of the body. SYN: linea mediana anterior [TA] .
arcuate l. [TA] an arching or bow-shaped l.. See arcuate l. of ilium, arcuate l. of rectus sheath. SYN: linea arcuata [TA] .
arcuate l. of ilium [TA] the iliac portion of the linea terminalis of the bony pelvis. SYN: linea arcuata ossis ilii [TA] .
arcuate l. of rectus sheath [TA] a crescentic l., not always clearly defined, which marks the lower limit of the posterior layer of the sheath of the rectus abdominis muscle. SYN: linea arcuata vaginae musculi recti abdominis [TA] , Douglas l., linea semicircularis, semicircular l..
arterial l. an intraarterial catheter.
axillary l. anterior axillary l., midaxillary l., posterior axillary l..
Baillarger lines two laminae of white fibers that course parallel to the surface of the cerebral cortex and are visible as the stria of the internal pyramidal layer [TA] in cortical layer V (outer l.) and the stria of the internal granular layer [TA] in cortical layer IV (inner l.) that appear in myelin stained sections cut perpendicular to the surface; the l. of Gennari in the calcarine cortex represents the outer of these lines. SYN: stria laminae granularis internae [TA] , stria laminae pyramidalis internae [TA] , Baillarger bands.
base l. See orbitomeatal plane (1) .
basinasal l. a l. connecting the basion and the nasion. SYN: nasobasilar l..
Beau lines transverse grooves on the fingernails following severe febrile disease, malnutrition, trauma, myocardial infarction, etc.
l. of Bechterew SYN: band of Kaes-Bechterew.
bismuth l. a black zone on the free marginal gingiva, often the first sign of poisoning from prolonged parenteral administration of bismuth.
black l. SYN: linea nigra.
lines of Blaschko a pattern of distribution of skin lesions or pigmentary anomalies; linear on the extremities, S-shaped curves on the abdomen, and V-shaped on the back, thought to result from genetic mosaicism (q.v.) and the interplay of transverse clonal proliferation and longitudinal growth and flexion of the embryo.
blue l. a bluish l. along the free border of the gingiva, occurring in chronic heavy metal poisoning.
Brödel bloodless l. l. running somewhat posterior to the lateral convex border of the kidney between anterior and posterior renal segments demarcating the areas of distribution of the anterior and posterior branches of the renal artery; it is in fact only relatively avascular.
Burton l. a bluish l. on the free border of the gingiva, occurring in lead poisoning.
calcification lines of Retzius incremental lines of rhythmic deposition of successive layers of enamel matrix during development. SYN: lines of Retzius.
Camper l. the l. running from the inferior border of the ala of the nose to the superior border of the tragus of the ear.
cell l. 1. in tissue culture, the cells growing in the first or later subculture from a primary culture. SEE ALSO: established cell l.. 2. a clone of cultured cells derived from an identified parental cell type.
cement l. the refractile boundary of an osteon or interstitial lamellar system in compact bone.
cervical l. a continuous anatomical irregular curved l. marking the cervical end of the crown of a tooth and the cementoenamel junction.
Chamberlain l. a l. drawn from the posterior margin of the hard palate to the dorsum of the foramen magnum; in basilar impression, the odontoid process rises above this l..
Chaussier l. the anteroposterior l. of the corpus callosum as appearing on median section of the brain.
choroid l. [TA] SYN: tenia choroidea.
Clapton l. a greenish discoloration of the marginal gingiva in cases of chronic copper poisoning.
cleavage lines SYN: tension lines.
Conradi l. a l. extending from the base of the ensiform cartilage to the apex beat of the heart, corresponding approximately to the lower edge of the cardiac area.
contour lines of Owen SYN: Owen lines.
Correra l. SYN: pleural lines.
costal l. of pleural reflection surface projection of the sharp l. along which the costal part of the parietal pleura becomes continuous with the diaphragmatic part inferiorly; this l. intersects midclavicular l. at the level of the 8th rib, the midaxillary l. at the level of the 10th rib, and the paravertebral l. at the level of the 12th rib; thoracentesis is performed one rib level higher in these lines.
costoclavicular l. SYN: parasternal l..
costophrenic septal lines SYN: Kerley B lines.
Crampton l. a l. from the apex of the cartilage of the last rib downward and forward nearly to the crest of the ilium, then forward parallel with it to a little below the anterior superior spine; a guide to the common iliac artery.
Daubenton l. the l. passing between the opisthion and the basion. SEE ALSO: Daubenton angle, Daubenton plane.
l. of demarcation a zone of inflammatory reaction separating a gangrenous area from healthy tissue.
demarcation l. of retina junction of avascular and vascular retina in retinopathy of prematurity; l. marking the limits of an old retinal detachment.
Dennie l. SYN: Dennie-Morgan fold.
dentate l. SYN: pectinate l..
developmental lines SYN: developmental grooves, under groove.
Douglas l. SYN: arcuate l. of rectus sheath.
Eberth lines lines appearing between the cells of the myocardium when stained with silver nitrate.
Egger l. seldom-used term for the circular l. of adhesion between the vitreous and posterior lens.
Ehrlich-Türk l. seldom-used term for the vertical, thin deposition of material on the posterior surface of the cornea in uveitis.
epiphysial l. [TA] the l. of junction of the epiphysis and diaphysis of a long bone where growth in length occurs. SYN: linea epiphysialis [TA] , synchondrosis epiphyseos.
established cell l. cells that demonstrate the potential for indefinite subculture in vitro.
Farre l. a whitish l. marking the insertion of the mesovarium at the hilum of the ovary.
Feiss l. a l. running from the medial malleolus to the plantar aspect of the first metatarsophalangeal joint.
Ferry l. an iron l. occurring in the corneal epithelium anterior to a filtering bleb.
l. of fixation a l. joining the object (or point of fixation) with the fovea.
Fleischner lines coarse linear shadows on a chest radiograph, indicating bands of subsegmental atelectasis.
Fraunhofer lines a number of the most prominent of the absorption lines of the solar spectrum.
fulcrum l. an imaginary l. around which a removable partial denture tends to rotate. SYN: rotational axis.
l. of Gennari a prominent white l. appearing in perpendicular sections of the visual cortex (Brodmann area 17) at about mid-thickness of the cortical gray matter, corresponding to the particularly well-developed outer l. of Baillarger of that cortical area, and composed largely of tangentially disposed intracortical association fibers. SYN: occipital stripe [TA] , stria occipitalis [TA] , occipital l.&star, Gennari band, Gennari stria, stripe of Gennari.
germ l. a collection of haploid cells derived from the specialized cells of the primitive gonad.
gluteal lines [TA] one of three rough curved lines on the outer surface of the ala of the ilium: anterior gluteal l., inferior gluteal l., and posterior gluteal l.; the two areas bounded by these give attachment to the gluteus minimus muscle below and gluteus medius above. SYN: lineae gluteae [TA] .
Granger l. on lateral skull radiographs, the l. produced by the groove of the optic chiasm or sulcus prechiasmaticus.
growth arrest lines dense lines parallel to the growth plates of long bones on radiographs, representing temporary slowing or cessation of longitudinal growth. SYN: Harris lines.
Gubler l. the level of the superficial origin of the trigeminus on the pons, a lesion below which causes Gubler paralysis.
gum l. the position of the margin of the gingiva in relation to the teeth in the dental arch.
Haller l. SYN: linea splendens.
Hampton l. a thin radiolucent band across the neck of a contrast-filled benign gastric ulcer, indicating mucosal edema. Cf.:Carman sign.
Harris lines SYN: growth arrest lines.
Head lines bands of cutaneous hyperesthesia associated with acute or chronic inflammation of the viscera. SYN: Head zones, tender lines, tender zones.
Hensen l. SYN: H band.
highest nuchal l. [TA] a l. above and parallel to the superior nuchal l. on the external surface of the occipital bone; it gives attachment to the epicranial aponeurosis and occipitalis muscle. SYN: linea nuchae suprema [TA] .
high lip l. the greatest height to which the lip is raised in normal function or during the act of smiling broadly.
Hilton white l. SYN: white l. of anal canal.
His l. a l. extending from the tip of the anterior nasal spine (acanthion) to the hindmost point on the posterior margin of the foramen magnum (opisthion), dividing the face into an upper and a lower, or dental part.
Holden l. the crease or furrow of the skin of the groin caused by flexion of the thigh.
Hudson-Stähli l. a brown, horizontal l. across the lower third of the cornea, occasionally seen in the aged and also in association with corneal opacities.
Hunter l. SYN: linea alba.
Hunter-Schreger lines SYN: Hunter-Schreger bands, under band.
iliopectineal l. SYN: linea terminalis of pelvis.
imbrication lines of von Ebner incremental lines in the dentin of the tooth that reflect variations in mineralization during dentin formation; the distance between the lines corresponds to the daily rate of dentin formation. SYN: incremental lines of von Ebner.
incremental lines 1. in the enamel, calcification lines of Retzius; 2. in the dentin, imbrication or incremental lines of von Ebner, and Owen lines.
incremental lines of von Ebner SYN: imbrication lines of von Ebner.
inferior nuchal l. [TA] a ridge that extends laterally from the external occipital crest toward the jugular process of the occipital bone. SYN: linea nuchae inferior [TA] .
inferior temporal l. of parietal bone [TA] the lower of two curved lines on the parietal bone; it marks the outer limit of attachment of the temporalis muscle. SYN: linea temporalis inferior ossis parietalis [TA] , temporal ridge.
infracostal l. SYN: subcostal plane.
intercondylar l. of femur [TA] a faint transverse ridge separating the floor of the intercondylar fossa from the popliteal surface of the femur; it affords attachment to the posterior portion of the articular capsule of the knee. SYN: linea intercondylaris femoris [TA] .
intermediate l. of iliac crest SYN: intermediate zone of iliac crest.
interspinal l. l. passing through both anterior superior iliac spines indicating the interspinal plane. SYN: linea interspinalis.
intertrochanteric l. [TA] a rough l. that separates the neck and shaft of the femur anteriorly; it passes downward and medially from the greater trochanter to the lesser trochanter and continues into the medial lip of the linea aspera. SYN: linea intertrochanterica [TA] , linea spiralis, spiral l..
intertubercular l. horizontal l. passing through tubercles of both iliac crests, indicating the intertubercular plane. SYN: linea intertubercularis.
iron l. deposition of iron in the corneal epithelium.
isoelectric l. the baseline of the electrocardiogram, recorded in the TP interval during rhythms with P waves.
l. of Kaes SYN: band of Kaes-Bechterew.
Kerley A lines images of deep interlobular septa; longer, thicker, and more central than Kerley B lines; usually in upper lobes.
Kerley B lines fine peripheral septal lines. SYN: costophrenic septal lines.
Kerley C lines a nonspecific fine reticular pattern on chest radiographs.
Kilian l. a transverse l. marking the promontory of the pelvis.
Langer lines SYN: tension lines.
Lanz l. SYN: interspinous plane.
lead l. deposits of lead sulfide in the gingiva in areas of chronic inflammation.
Looser lines radiolucent bands in the cortex of a bone; usually indicates osteomalacia. SYN: Looser zones.
low lip l. 1. the lowest position of the lower lip during the act of smiling or voluntary retraction; 2. the lowest position of the upper lip at rest.
M l. a fine l. in the center of the A band of the sarcomere of striated muscle myofibrils. SYN: M band, mesophragma.
Mach l. the apparent l. of contrasting density bordering a soft tissue shadow on a radiograph; it is an optical illusion constructed by the observer's retina.
mammary l. a transverse l. drawn between the two nipples.
mammillary l. [TA] a vertical l. passing through the nipple on either side. SYN: linea mammillaris [TA] , nipple l..
McKee l. a l. drawn from the tip of the cartilage of the eleventh rib to a point 3.5 cm medial to the anterior superior spine, then curved downward, forward, and inward to just above the deep inguinal ring; a guide to the common iliac artery.
median l. anterior median l., posterior median l..
Mees lines horizontal white bands of the nails seen in chronic arsenical poisoning, and occasionally in leprosy. SYN: Mees stripes.
mercurial l. a bluish brown pigmentation seen at the gingival margin and associated with mercury poisoning (mercurial stomatitis).
Meyer l. a l. through the axis of the big toe and passing the midpoint of the heel in a normal foot.
midaxillary l. [TA] a vertical l. intersecting a point midway between the anterior and posterior axillary folds or lines. SYN: linea axillaris media [TA] , linea medio-axillaris, middle axillary l..
midclavicular l. [TA] a vertical l. passing through the midpoint of the clavicle. SYN: linea medioclavicularis [TA] .
middle axillary l. SYN: midaxillary l..
milk l. SYN: mammary ridge.
Monro l. SYN: Monro-Richter l..
Monro-Richter l. a l. passing from the umbilicus to the anterior superior iliac spine. McBurney point occurs on this l.. SYN: Monro l., Richter-Monro l..
Muehrcke lines white lines, parallel with the lunula and separated from each other by normal pink areas; associated with hypoalbuminemia; the lines do not move outward with nail growth, but disappear when the serum albumin returns to normal.
mylohyoid l. [TA] a ridge on the inner surface of the mandible running from a point inferior to the mental spine upward and backward to the ramus behind the last molar tooth; it gives attachment to the mylohyoid muscle and the lowermost part of the superior constrictor of the pharynx. SYN: linea mylohyoidea [TA] , mylohyoid ridge.
nasobasilar l. SYN: basinasal l..
Nélaton l. a l. drawn from the anterior superior iliac spine to the tuberosity of the ischium; normally the greater trochanter lies in this l., but in cases of iliac dislocation of the hip or fracture of the neck of the femur the trochanter is felt above the l.. SYN: Roser-Nélaton l..
neonatal l. in deciduous teeth, a l. of demarcation between prenatal and postnatal enamel. SYN: neonatal ring.
nipple l. SYN: mammillary l..
Obersteiner-Redlich l. SYN: Obersteiner-Redlich zone.
oblique l. [TA] a diagonal, sloping or slanting l.; a l. which is neither parallel nor perpendicular, neither horizontal nor vertical. See oblique l. of mandible, oblique l. of thyroid cartilage. SYN: linea obliqua [TA] .
oblique l. of mandible [TA] the l. on the external surface of the mandible that extends from the mental tubercle to the ramus and separates the alveolar and basilar parts of the bone. SYN: linea obliqua mandibulae [TA] , external oblique ridge.
oblique l. of thyroid cartilage [TA] a ridge on the outer surface of the thyroid cartilage that gives attachment to the sternothyroid and thyrohyoid muscles. SYN: linea obliqua cartilaginis thyroideae [TA] .
occipital l. l. of Gennari.
l. of occlusion the alignment of the occluding surfaces of the teeth in the horizontal plane. SEE ALSO: occlusal plane.
Ogston l. a l. drawn from the adductor tubercle of the femur to the intercondylar notch; a guide to resection of the medial condyle for knock-knee.
Ohngren l. a theoretical plane passing between the medial canthus of the eye and the angle of the mandible; used as an arbitrary dividing l. in classifying localized tumors of the maxillary sinus; tumors above the l. invade vital structures early and have a poorer prognosis, whereas those below the l. have a more favorable prognosis.
orbitomeatal l. See orbitomeatal plane.
Owen lines accentuated incremental lines in the dentin thought to be due to disturbances in the mineralization process. SYN: contour lines of Owen.
paraspinal l. radiographic image of the interface between the lung and paravertebral soft tissues.
parasternal l. [TA] a vertical l. equidistant from the sternal and midclavicular lines. SYN: linea parasternalis [TA] , costoclavicular l..
paravertebral l. [TA] a vertical l. corresponding to the tips of the transverse processes of the vertebrae. SYN: linea paravertebralis [TA] .
Paris l. a unit of microscopic measurement as used in Kölliker's Mikroskopische Anatomie; it was equal to 0.0888138 of an inch.
Paton lines SYN: striae retinae, under stria.
pectinate l. [TA] the l. between the simple columnar epithelium of the rectum and the stratified epithelium of the anal canal, usually defined as being at the level of the anal valves at the bases of the anal columns. SYN: linea pectinata canalis analis [TA] , dentate l..
pectineal l. of femur [TA] a ridge running down the posterior surface of the shaft of the femur from the lesser trochanter to which the pectineus muscle attaches; continuous superiorly with intertrochanteric l. and inferiorly with the medial lip of the linea aspera. SYN: linea pectinea femoris [TA] .
pectineal l. of pubis SYN: pecten pubis.
PICC l. acronym for peripherally inserted central catheter; a long-term central venous catheter, inserted peripherally.
pleural lines on a chest radiograph, the shadow of the soft tissues between the aerated lung and the bones of the thorax. SYN: Correra l., pleural stripe.
lines of pleural reflection lines, usually projected onto the surface of the thoracic wall, indicating the abrupt change in direction of the parietal pleura as it passes from one wall of the pulmonary cavity to another. SEE ALSO: vertebral l. of pleural reflection.
pleuroesophageal l. on a frontal chest radiograph, the image of the interface between the right lung and esophagus, the boundary of the azygoesophageal recess.
Poirier l. a l. extending from the nasion to the lambda.
popliteal l. SYN: soleal l..
postaxillary l. SYN: posterior axillary l..
posterior axillary l. [TA] a vertical l. extending inferiorly from the posterior axillary fold. SYN: linea axillaris posterior [TA] , linea postaxillaris, postaxillary l..
posterior junction l. radiographic image of the mediastinal septum between the upper lobes behind the esophagus, above the aortic arch.
posterior median l. [TA] the l. of intersection of the midsagittal plane with the posterior surface of the body. SYN: linea mediana posterior [TA] .
Poupart l. a vertical l. passing through the center of the inguinal ligament on either side; it marks off the hypochondriac, lumbar, and iliac from the epigastric, umbilical, and hypogastric regions, respectively.
preaxillary l. SYN: anterior axillary l..
Reid base l. a l. drawn from the inferior margin of the orbit to the auricular point (center of the orifice of the external acoustic meatus) and extending backward to the center of the occipital bone. Used as the zero plane in computed tomography.
retentive fulcrum l. 1. an imaginary l. connecting the retentive points of clasp arms on retaining teeth adjacent to mucosa-borne denture bases; 2. an imaginary l. connecting the retentive points of clasp arms, around which l. the denture tends to rotate when subjected to forces such as the pull of sticky foods.
lines of Retzius SYN: calcification lines of Retzius.
Richter-Monro l. SYN: Monro-Richter l..
Roser-Nélaton l. SYN: Nélaton l..
rough l. SYN: linea aspera.
sagittal l. any l. parallel to the midline, indicating (occurring within) a sagittal plane.
Salter incremental lines transverse lines sometimes seen in dentin, due to improper calcification.
S-BP l. a l. connecting the sella with the Bolton point; it indicates the posterior portion of the cranial base in cephalometrics.
scapular l. [TA] a vertical l. passing through the inferior angle of the scapula. SYN: linea scapularis [TA] .
Schreger lines SYN: Hunter-Schreger bands, under band.
semicircular l. SYN: arcuate l. of rectus sheath.
semicircular l. of Douglas a crescent-shaped l. that defines the end of the posterior fascial sheath of the rectus abdominis muscle.
semilunar l. SYN: linea semilunaris.
septal lines radiographic images of thickened interlobular septa, most often along the lateral border of lung, extending to pleura; Kerley A and B lines; usually caused by septal edema and fibrosis, also carcinomatosis.
Sergent white l. SYN: white l. (2) .
Shenton l. a curved l. formed by the top of the obturator foramen and the inner side of the neck of the femur, seen on an anteroposterior frontal radiograph of a normal hip joint; it is disturbed in lesions of the joint such as dislocation or fracture.
S-N l. a l. connecting a point (S) representing the center of the sella turcica with the frontonasal junction (N); it denotes the anterior portion of the cranial base in cephalometrics.
soleal l. [TA] a ridge that extends obliquely downward and medially across the back of the tibia from the fibular articular facet; it gives origin to the soleus muscle. SYN: linea musculi solei [TA] , l. for soleus muscle, linea poplitea, popliteal l..
l. for soleus muscle SYN: soleal l..
Spigelius l. SYN: linea semilunaris.
spiral l. SYN: intertrochanteric l..
stabilizing fulcrum l. an imaginary l. connecting occlusal rests, around which l. the denture tends to rotate under masticatory force.
sternal l. [TA] a vertical l. corresponding to the lateral margin of the sternum. SYN: linea sternalis [TA] .
sternal l. of pleural reflection surface projection of the sharp l. along which the costal part of the parietal pleura becomes continuous with the mediastinal part anteriorly; the right and left sternal lines of pleural reflection are parallel to the median plane, posterior to the sternum, at the level of costal cartilages 2–4; at the level of the costal cartilage 4, the left l. turns laterally to parallel the left margin of the sternum, creating a “notch” that is shallower than the cardiac notch of the left lung and an area where the pericardial sac contacts the anterior thoracic wall without intervening pleura sac—significant for pericardiocentesis.
Stocker l. a fine l. of pigment in the corneal epithelium near the head of a pterygium.
subcostal l. a transverse l. transecting the inferiormost border of the thoracic cage, indicating the subcostal plane. SEE ALSO: subcostal plane. SYN: linea subcostalis.
superior nuchal l. [TA] the ridge that extends laterally from the external occipital protuberance toward the lateral angle of the occipital bone; it gives attachment to the trapezius, sternocleidomastoid, and splenius capitis muscles. SYN: linea nuchae superior [TA] .
superior temporal l. of parietal bone [TA] the upper of two curved lines on the parietal bone; the temporal fascia is attached to it. SYN: linea temporalis superior ossis parietalis [TA] , temporal ridge.
supracrestal l. a transverse l. transecting the high point of both iliac crests, indicating the supracristal plane. SEE ALSO: supracristal plane. SYN: linea supracristalis.
survey l. 1. a l. scribed on an abutment tooth of a dental cast by means of a dental surveyor indicating the height of contour of the tooth according to a specific path of insertion; 2. a l. which serves as a guide in the proper location of various parts of a clasp assembly for a removable partial denture. SYN: clasp guideline, Cummer guideline.
Sydney l. SYN: Sydney crease.
sylvian l. the l. of the posterior limb of the lateral sulcus (sylvian fissure) of the cerebral cortex.
temporal l. inferior temporal l. of parietal bone, superior temporal l. of parietal bone.
temporal l. of frontal bone [TA] anterior continuation of the inferior temporal l. of the temporal bone onto the lateral aspect of the external surface of the frontal bone, demarcating the temporal surface of the bone. SYN: linea temporalis ossis frontalis [TA] .
tender lines SYN: Head lines.
tension lines [TA] lines that can be extrapolated by connecting linear openings made when a round pin is driven into the skin of a cadaver, resulting from the principal axis of orientation of the subcutaneous connective tissue (collagen) fibers of the dermis; they vary in direction with the region of the body surface. SYN: lineae distractionis [TA] , cleavage lines, Langer lines.
terminal l. SYN: linea terminalis of pelvis.
Topinard l. a l. running between the glabella and the mental point.
tram lines the images of bronchial walls on a plain chest radiograph. When seen distally, indicative of bronchiectasis or chronic bronchitis; usually thickened; colloq., British. SYN: radiographic parallel l. shadow.
trapezoid l. [TA] the area on the inferior surface of the clavicle near its lateral extremity on which the trapezoid ligament attaches. SYN: linea trapezoidea [TA] , trapezoid ridge.
Ullmann l. the l. of displacement in spondylolisthesis.
vertebral l. of pleural reflection approximation of the more gradual reflection of the costal part of the parietal pleura onto the mediastinum posteriorly.
Vesling l. SYN: raphe of scrotum.
vibrating l. the imaginary l. across the posterior part of the palate, marking the division between the movable and immovable tissues.
l. of vision SYN: visual axis.
Wegner l. a narrow, whitish, slightly curved l. representing an area of preliminary calcification at the junction of the epiphysis and diaphysis of a long bone, related to syphilitic epiphysitis.
white l. 1. SYN: linea alba. 2. a pale streak appearing within 30 to 60 seconds after stroking the skin with a fingernail, and lasting for several minutes; regarded as a sign of diminished arterial tension. SYN: Sergent white l..
white l. of anal canal a bluish pink, narrow, wavy zone in the mucosa of the anal canal below the pectinate l. at the level of the interval between the subcutaneous part of the external sphincter and the lower border of the internal sphincter, said to be palpable. SYN: Hilton white l..
white l. of Toldt 1. lateral reflection of posterior parietal pleura of abdomen over the mesentery of the ascending and descending colon. 2. junction of parietal peritoneum with Denonvilliers fascia.
Z l. a cross-striation bisecting the I band of striated muscle myofibrils and serving as the anchoring point of actin filaments at either end of the sarcomere. SYN: intermediate disk, Z band, Z disk.
lines of Zahn riblike markings seen by the naked eye on the surface of antemortem thrombi; they consist of a branching framework of platelets and fibrin separating the coagulated blood cells. SYN: striae of Zahn.
Zöllner lines figures devised to show the possibility of optical illusions; a common one consists of two parallel lines which are met by numerous short lines obliquely placed; the parallel lines then seeming to converge or diverge.

linea
linea, gen. and pl. lineae (lin′e-a, -e-e) [TA]

SYN: line. [L.]
l. alba [TA] a fibrous band running vertically the entire length of the midline of the anterior abdominal wall, receiving the attachments of the oblique and transverse abdominal muscles. SYN: Hunter line, white line (1) .
l. anorectalis [TA] SYN: anocutaneous line.
l. arcuata [TA] SYN: arcuate line.
l. arcuata ossis ilii [TA] SYN: arcuate line of ilium.
l. arcuata vaginae musculi recti abdominis [TA] SYN: arcuate line of rectus sheath. SEE ALSO: rectus sheath, posterior layer of rectus sheath.
l. aspera [TA] a rough ridge with two pronounced lips running down the posterior surface of the shaft of the femur; the lateral lip of the l. aspera is a continuation of the gluteal tuberosity, the medial lip of the intertrochanteric line; it affords attachment to the vastus medialis, adductor longus, adductor magnus, adductor brevis, the short head of the biceps, and the vastus lateralis muscles as well as to the intermuscular septa of the thigh. SYN: rough line.
lineae atrophicae SYN: striae cutis distensae, under stria.
l. axillaris anterior [TA] SYN: anterior axillary line.
l. axillaris media [TA] SYN: midaxillary line.
l. axillaris posterior [TA] SYN: posterior axillary line.
l. corneae senilis SYN: arcus senilis.
lineae distractionis [TA] SYN: tension lines, under line.
l. epiphysialis [TA] SYN: epiphysial line.
l. glutea anterior anterior gluteal line. See gluteal lines, under line.
lineae gluteae [TA] SYN: gluteal lines, under line.
l. glutea inferior inferior gluteal line. See gluteal lines, under line.
l. glutea posterior posterior gluteal line. See gluteal lines, under line.
l. intercondylaris femoris [TA] SYN: intercondylar line of femur.
l. intermedia cristae iliacae [TA] SYN: intermediate zone of iliac crest.
l. interspinalis SYN: interspinal line. SEE ALSO: interspinous plane.
l. intertrochanterica [TA] SYN: intertrochanteric line.
l. intertubercularis SYN: intertubercular line. SEE ALSO: intertubercular plane.
l. mammillaris [TA] SYN: mammillary line.
l. mediana anterior [TA] SYN: anterior median line.
l. mediana posterior [TA] SYN: posterior median line.
l. medio-axillaris SYN: midaxillary line, midaxillary line.
l. medioclavicularis [TA] SYN: midclavicular line.
l. musculi solei [TA] SYN: soleal line.
l. mylohyoidea [TA] SYN: mylohyoid line.
l. nigra the l. alba in pregnancy, which then becomes pigmented. SYN: black line.
l. nuchae inferior [TA] SYN: inferior nuchal line.
l. nuchae mediana SYN: external occipital crest.
l. nuchae superior [TA] SYN: superior nuchal line.
l. nuchae suprema [TA] SYN: highest nuchal line.
l. obliqua [TA] SYN: oblique line.
l. obliqua cartilaginis thyroideae [TA] SYN: oblique line of thyroid cartilage.
l. obliqua mandibulae [TA] SYN: oblique line of mandible.
l. parasternalis [TA] SYN: parasternal line.
l. paravertebralis [TA] SYN: paravertebral line.
l. pectinata canalis analis [TA] SYN: pectinate line.
l. pectinea femoris [TA] SYN: pectineal line of femur.
l. poplitea SYN: soleal line.
l. postaxillaris SYN: posterior axillary line, posterior axillary line.
l. preaxillaris SYN: anterior axillary line, anterior axillary line.
l. scapularis [TA] SYN: scapular line.
l. semicircularis SYN: arcuate line of rectus sheath.
l. semilunaris [TA] the slight groove in the external abdominal wall parallel to the lateral edge of the rectus sheath. SYN: semilunar line, Spigelius line.
l. spiralis SYN: intertrochanteric line.
l. splendens a thickened band of pia mater along the midline of the anterior surface of the spinal cord. SYN: Haller line.
l. sternalis [TA] SYN: sternal line.
l. subcostalis SYN: subcostal line. SEE ALSO: subcostal plane.
l. supracristalis SYN: supracrestal line. SEE ALSO: supracrestal plane.
l. temporalis inferior ossis parietalis [TA] SYN: inferior temporal line of parietal bone.
l. temporalis ossis frontalis [TA] SYN: temporal line of frontal bone.
l. temporalis superior ossis parietalis [TA] SYN: superior temporal line of parietal bone.
l. terminalis of pelvis [TA] an oblique ridge on the inner surface of the ilium and continued on the pubis, which forms the lower boundary of the iliac fossa; it separates the true from the false pelvis. SYN: l. terminalis pelvis [TA] , iliopectineal line, terminal line.
l. terminalis pelvis [TA] SYN: l. terminalis of pelvis.
lineae transversae ossis sacri [TA] SYN: transverse ridges of sacrum, under ridge.
l. trapezoidea [TA] SYN: trapezoid line.

lineage
lineage (lin′aj, lin′e-aj)

Descent in a line from a common progenitor or source. [O. Fr. ligne, line of descent]

linear
linear (lin′e-ar)

Pertaining to or resembling a line.

linearity
linearity (lin-e-ar′i-te)

A relationship between two quantities whereby a change in one causes a directly proportional change in the other. [L. linearis, linear, fr. linea, line]

linebreeding
linebreeding

Practice of successive inbreeding of closely related individuals with the object of concentrating desirable or scientifically interesting genetic characteristics of some individual or group.

liner
liner (li′ner)

A layer of protective material.
asbestos l. a layer of asbestos used to line a dental casting ring so that during the heating and expansion of the investment the compression of the l. will free the investment from the restraint of the ring.
cavity l. SYN: varnish (dental).

LINES
LINES

Abbreviation for long interspersed elements, under element.

Lineweaver
Lineweaver

Hans, U.S. physical chemist, *1907. See L.-Burk equation, L.-Burk plot.

Ling
Ling

Per Henrik, Swedish hygienist, 1776–1839. See L. method.

Lingelsheimia
Lingelsheimia (lin′jels-hii′me-a)

SYN: Acinetobacter. [W. von Lingelsheim]
L. anitrata SYN: Acinetobacter calcoaceticus.

lingua
lingua, gen. and pl. linguae (ling′gwa, ling′gwe)

1. SYN: tongue (1) . 2. SYN: tongue (2) . [L. tongue]
l. cerebelli SYN: lingula of cerebellum.
l. fissurata SYN: fissured tongue.
l. frenata a tongue with a very short frenum constituting tongue-tie.
l. geographica
l. nigra SYN: black tongue.
l. plicata SYN: fissured tongue.

lingual
lingual (ling′gwal)

1. Relating to the tongue or any tonguelike part. SYN: glossal. 2. Next to or toward the tongue.

Linguatula
Linguatula (ling-gwat′u-la)

A genus of endoparasitic bloodsucking arthropods (family Linguatulidae, class Pentastomida), commonly known as tongue worms; once thought to be degenerate Acarina, but now generally considered to be a small but distinctive early offshoot of the Arthropoda. Adult worms are found in lungs or air passages of various hosts ( e.g., reptiles, birds, carnivores); young worms are found in a great variety of hosts, including humans, but chiefly in animals that serve as prey. [L. linguatu, tongued, + -ula, dim. suffix]
L. rhinaria SYN: L. serrata.
L. serrata a species most common in Europe, but also found in the United States, South America, and probably elsewhere; the adult is a whitish, soft, flattened, annulated worm equipped with hooks by which it attaches itself to the nasal mucosa of dogs and other canids; the larvae develop in the liver and lymph nodes of rodents, swine, cattle, and sometimes humans and other primates. SYN: L. rhinaria.

linguatuliasis
linguatuliasis (ling-gwat-u-li′a-sis)

Infection with Linguatula. SEE ALSO: halzoun.

Linguatulidae
Linguatulidae (ling-gwat′u-li-de)

One of the families of Pentastomida of medical interest, the other being the Porocephalidae. L. have flattened bodies; adults inhabit the nasal cavities of various carnivores, such as the dog and cat, and larval forms are found in tissues of rodents, herbivores, and other animals; both larvae and adults have been reported from humans.

linguiform
linguiform (ling′gwi-form)

Tongue-shaped.

lingula
lingula, pl .lingulae (ling′gu-la, -le) [TA]

1. A term applied to several tongue-shaped processes. 2. When not qualified, the l. of cerebellum. [L. dim. of lingua, tongue]
l. cerebelli [TA] SYN: l. of cerebellum.
l. of cerebellum [TA] a tongue-shaped sequence of flattened cerebellar folia forming the anterior (or superior) extreme of the cerebellar vermis, extending forward on the surface of the superior medullary velum between the two emerging superior cerebellar peduncles. SYN: l. cerebelli [TA] , alae lingulae cerebelli, lingua cerebelli, tongue of cerebellum.
l. of left lung [TA] an inferomedial projection from the anterior aspect of the upper lobe of the left lung which bounds the cardiac notch inferiorly. SYN: l. pulmonis sinistri [TA] .
l. of mandible [TA] a pointed tongue of bone overlapping the mandibular foramen, giving attachment to the sphenomandibular ligament. SYN: l. mandibulae [TA] , mandibular tongue, Spix spine.
l. mandibulae [TA] SYN: l. of mandible.
l. pulmonis sinistri [TA] SYN: l. of left lung.
sphenoidal l. [TA] a slender process projecting posteriorly between the body and greater wing of the sphenoid bone, on either side, forming the lateral margin of the carotid groove. In the dry skull, it projects into the foramen lacerum. SYN: l. sphenoidalis [TA] .
l. sphenoidalis [TA] SYN: sphenoidal l..

lingular
lingular (ling′gu-lar)

Pertaining to any lingula.

lingulectomy
lingulectomy (ling′gu-lek′to-me)

Excision of the lingular portion of the left upper lobe of the lung.

linguo- linguo-

The tongue. [L. lingua]

linguoclination
linguoclination (ling′gwo-kli-na′shun)

Axial inclination of a tooth when the crown is inclined toward the tongue more than is normal.

linguoclusion
linguoclusion (ling-gwo-kloo′zhun)

Displacement of a tooth toward the interior of the dental arch, or toward the tongue. SEE ALSO: lingual occlusion (2) . SYN: lingual occlusion (1) .

linguodistal
linguodistal (ling-gwo-dis′tal)

Relating to the lingual and distal part of the tooth, e.g., the l. cusp. SEE ALSO: distolingual.

linguogingival
linguogingival (ling-gwo-jin′ji-val)

1. Relating to the gingival third of the lingual surface of a tooth. 2. Relating to the angle or point of junction of the lingual border and gingival line on the distal or mesial surface of an incisor tooth.

linguo-occlusal
linguo-occlusal (ling′gwo-o-kloo′sal)

Relating to the line of junction of the lingual and occlusal surfaces of a tooth.

linguopapillitis
linguopapillitis (ling′gwo-pap′i-li′tis)

Small painful ulcers involving the papillae on the tongue margins.

linguoplate
linguoplate (ling′gwo-plat)

A partial denture major connector formed as a lingual bar extended to cover the cingula of the lower anterior teeth. SYN: lingual plate.

linguoversion
linguoversion (ling′gwo-ver-zhun)

Malposition of a tooth lingual to the normal position.

liniment
liniment (lin′i-ment)

A liquid preparation for external application or application to the gums; they may be clear dispersions, suspensions, or emulsions, and are frequently applied by friction to the skin; used as counterirritants, rubefacients, anodynes, or cleansing agents. [L., fr. lino, to smear]

linin
linin (li′nin)

1. A bitter glycoside obtained from Linum catharticum (family Linaceae). 2. A protein in linseed. 3. Obsolete term for the threadlike, nonstaining (achromatic) substance of the cell nucleus, on which chromatin granules were thought to be suspended. [L. linum, fr. G. linon, flax]

lining
lining (lin′ing)

A coating applied to the pulpal wall(s) of a restorative dental preparation to protect the pulp from thermal or chemical irritation; usually a vehicle containing a varnish, resin, and/or calcium hydroxide.

linitis
linitis (li-ni′tis, li-ni′tis)

Inflammation of cellular tissue, specifically of the perivascular tissue of the stomach. [G. linon, flax, linen cloth, + -itis, inflammation]
l. plastica originally believed to be an inflammatory condition, but now recognized to be due to infiltrating scirrhous carcinoma causing extensive thickening of the wall of the stomach; often called leather-bottle stomach.

link
link

A connection; bond.
tip links connections between the stereocilia of auditory and vestibular hair cells.

linkage
linkage (lingk′ij)

1. A chemical covalent bond. 2. The relationship between syntenic loci sufficiently close that the respective alleles are not inherited independently by the offspring; a characteristic of loci, not genes.
genetic l. l. (2) .
medical record l. the assemblage of lifetime or long-term individual medical histories from vital and medical data derived from multiple sources.
record l. a method of assembling the information contained in two or more sets of medical records, or a set of medical records and vital records such as birth or death certificates, and a procedure to ensure that each individual's records are counted only once; facilitated by a unique numbering system such as the Hogben number or soundex code to identify individuals with precision.
sex l. inheritance of a trait or a sex chromosome or gonosome. A man receives all his sex-linked genes from his mother and transmits them all to his daughters but not to his sons; a recessive sex-linked character is much more likely to be expressed in the male. SEE ALSO: sex chromosomes, under chromosome.

linked
linked

Said of two genetic loci that exhibit genetic linkage.

linker
linker

A fragment of synthetic DNA containing a restriction site that may be used for splicing genes.

linker scanning
linker scanning

A type of deletion mutagenesis where the distance and/or reading frame between potentially important regions is maintained by replacement with a synthetic oligonucleotide of known sequence.

Linné
Linné

Carl von, Swedish botanist and physician, 1707-1778. See linnaean system of nomenclature.

Linognathus
Linognathus (li-nog′na-thus)

A genus of sucking lice (order Anoplura, family Linognathidae) that includes the species L. africanus, the African blue louse of sheep and goats; L. ovillus, the sheep body louse; L. pedalis, the foot louse of sheep; L. setosus, the sucking louse of the dog and other canids; L. stenopsis, the sucking louse of goats; and L. vituli, the “long-nosed” sucking louse, ox louse, or blue louse of cattle. [G. linon, flax, thread, + gnathos, jaw]

linoleate
linoleate (li-no′le-at)

Salt of linoleic acid.

linoleic acid
linoleic acid (lin-o-le′ik)

9,12-Octadecadienoic acid;a doubly unsaturated fatty acid, occurring widely in plant glycerides, that is essential in nutrition in mammals. SYN: linolic acid. [L. linum, flax, + oleum, oil]

linolenic acid
linolenic acid (lin-o-len′ik)

9,12,15-Octadecatrienoic acid (also referred to as α-l);an unsaturated fatty acid that is essential in the nutrition of mammals. γ-l. is 6,9,12-octadecatrienoic acid.

linolic acid
linolic acid

SYN: linoleic acid.

linseed
linseed (lin′sed)

The dried ripe seed of Linum usitatissimum (family Linaceae), flax, the fiber of which is used in the manufacture of linen; an infusion was used as a demulcent in catarrhal affections of the respiratory and urogenital tracts, and the ground seeds are used in making poultices. SYN: flaxseed. [G. linon, flax]
l. oil a fatty oil expressed from the ripe seeds of Linum usitatissimum; used in the preparation of lime liniment. SYN: flaxseed oil.

lint
lint

A soft, absorbent material rarely used in surgical dressings, usually in the form of a thick, loosely woven material (sheet or patent l.). [O.E. lin, flax]

lio- lio-

See leio-.

LIP
LIP

Acronym for lymphocytic interstitial pneumonia or lymphoid interstitial pneumonia. See lymphocytic interstitial pneumonia.

lip
lip [TA]

1. One of the two muscular folds with an outer membrane having a stratified squamous cell epithelial surface layer that bound the mouth anteriorly. 2. Any liplike structure bounding a cavity or groove. SEE ALSO: labium, labrum. SYN: labium (1) [TA] . [A.S. lippa]
acetabular l. SYN: acetabular labrum.
anterior l. of external os of uterus [TA] the portion of the vaginal part of the uterine cervix that bounds the ostium anteriorly intervening between the ostium and the anterior vaginal fornix. It is slightly shorter than the posterior l.. SYN: labium anterius ostii uteri [TA] , anterior l. of uterine os.
anterior l. of uterine os SYN: anterior l. of external os of uterus.
articular l. SYN: labrum (3) .
cleft l. a congenital facial abnormality of the l. (usually of the upper l.) resulting from failure of union of the medial and lateral nasal prominences and maxillary process; frequently but not necessarily associated with cleft alveolus and cleft palate. In many families and in various forms [MIM*119300, *119500, *119530, *119540, and *119550] there seems to be autosomal dominant inheritance; likewise for X-linked inheritance [MIM*303400]. But generally, as with the supposed autosomal recessive forms, the genetics is more confusing and may represent a variable feature of a syndrome. SYN: harelip.
double l. congenital or acquired excess tissue on the inner mucosal aspect of the l.; may be a manifestation of Ascher syndrome.
external l. of iliac crest SYN: outer l. of iliac crest.
glenoidal l. SYN: glenoid labrum of scapula.
Hapsburg l. Hapsburg jaw.
inner l. of iliac crest [TA] the roughened inner margin of the crest that gives attachment to parts of the transversus abdominis, quadratus lumborum, and erector spinae muscles. SYN: labium internum cristae iliacae [TA] , internal l. of iliac crest.
internal l. of iliac crest SYN: inner l. of iliac crest.
large pudendal l. SYN: labium majus.
lateral l. of linea aspera [TA] the lateral margin of the linea aspera of the femur that gives attachment to the lateral intermuscular septum and the short head of the biceps femoris muscles. SYN: labium laterale lineae asperae [TA] .
lower l. [TA] the muscular fold bounding the opening of the mouth inferiorly. SYN: labium inferius oris [TA] .
medial l. of linea aspera [TA] the medial margin of the linea aspera of the femur that provides attachment for part of the vastus medialis muscle. SYN: labium mediale lineae asperae [TA] .
lips of mouth [TA] fleshy folds with skin externally and oral mucosa internally that surround the oval fissure and form the anterior walls of the oral vestibule; with the enclosed orbicularis oris and various dilator muscles, the lips constitute the cranial sphincter of the alimentary tract. SYN: labia oris [TA] .
outer l. of iliac crest [TA] the roughened outer margin of the crest that gives attachment to the external oblique and latissimus dorsi muscles above and to the fascia lata and the tensor fasciae latae muscle below. SYN: labium externum cristae iliacae [TA] , external l. of iliac crest.
posterior l. of external os of uterus [TA] the portion of the uterine cervix that bounds the ostium posteriorly. It is slightly longer than the anterior l., intervening between the cervical canal and the posterior fornix of the vagina. SYN: labium posterius ostii uteri [TA] .
rhombic l. the thickened alar plate of the embryonic rhombencephalon.
small pudendal l. SYN: labium minus.
tympanic l. of limbus of spiral lamina SYN: tympanic l. of spiral limbus.
tympanic l. of spiral limbus [TA] the lower, long periosteal extension of the limbus laminae spiralis osseae that rests on the basilar lamina of the spiral organ (of Corti). SYN: labium limbi tympanicum limbi spiralis ossei [TA] , labium limbi tympanicum laminae spiralis ossei, tympanic labium of limbus of spiral lamina, tympanic l. of limbus of spiral lamina.
upper l. [TA] the muscular fold forming the superior border of the mouth. SYN: labium superius oris [TA] .
vestibular l. of limbus of spiral lamina SYN: vestibular l. of spiral limbus.
vestibular l. of spiral limbus [TA] the upper, short periosteal extension of the limbus laminae spiralis osseae which provides the central attachment for the tectorial membrane. SYN: labium limbi vestibulare limbi spiralis ossei [TA] , labium limbi vestibulare laminae spiralis ossei, lamina dentata, vestibular labium of limbus of spiral lamina, vestibular l. of limbus of spiral lamina.

lip- lip-

See lipo-.

lipancreatin
lipancreatin (li-pan′kre-a-tin, -kre′a-tin)

SYN: pancrelipase.

liparocele
liparocele (lip′a-ro-sel)

An omental hernia. [G. liparos, fatty, + kele, tumor, hernia]

lipase
lipase (lip′as)

1. In general, any fat-splitting or lipolytic enzyme; a carboxylesterase; e.g., triacylglycerol l., phospholipase A₂, lipoprotein l.. 2. SYN: triacylglycerol l..

lipectomy
lipectomy (lip-ek′to-me)

Surgical removal of fatty tissue, as in cases of adiposity. [lipo- + G. ektome, excision]

lipedema
lipedema (lip′e-de′ma)

Chronic swelling, usually of the lower extremities, particularly in middle-aged women, caused by the widespread even distribution of subcutaneous fat and fluid. [lipo- + G. oidema, swelling]

lipemia
lipemia (lip-e′me-a)

The presence of an abnormally high concentration of lipids in the circulating blood. SYN: hyperlipidemia, hyperlipoidemia, lipidemia, lipoidemia. [lipid + G. haima, blood]
alimentary l. relatively transient l. occurring after the ingestion of foods with a large content of fat. SYN: postprandial l..
diabetic l. development of lactescent plasma upon ingestion of dietary lipids; a rare manifestation of uncontrolled diabetes mellitus caused by defective metabolism of dietary lipids and abolished by the administration of insulin.
postprandial l. SYN: alimentary l..
l. retinalis a creamy appearance of the retinal blood vessels that occurs when the lipids of the blood exceed 5%.

lipemic
lipemic (li-pe′mik)

Relating to lipemia.

lipid
lipid (lip′id)

“Fat-soluble,” an operational term describing a solubility characteristic, not a chemical substance, i.e., denoting substances extracted from animal or vegetable cells by nonpolar solvents; included in the heterogeneous collection of materials thus extractable are fatty acids, glycerides and glyceryl ethers, phospholipids, sphingolipids, long-chain alcohols and waxes, terpenes, steroids, and “fat-soluble” vitamins such as A, D, and E. [G. lipos, fat]
l. A the glycolipid component of lipopolysaccharide responsible for its endotoxic activity.
anisotropic l. a l. in the form of doubly refractive droplets.
anular l. the layer(s) of l. bound to and/or surrounding an integral membrane protein.
brain l. impure cephalin possessing marked hemostatic action when locally applied.
compound lipids lipids that can be hydrolyzed under alkali conditions to generate smaller constituents.
isotropic l. a l. occurring in the form of singly refractive droplets.
simple lipids SYN: homolipids.

lipidemia
lipidemia (lip′i-de′me-a)

SYN: lipemia.

lipidolytic
lipidolytic (lip′i-do-lit′ik)

Causing breakdown of lipid. [lipid + G. lysis, loosening]

lipidosis
lipidosis, pl .lipidoses (lip-i-do′sis, -sez)

Hereditary abnormality of lipid metabolism that results in abnormal amounts of lipid deposition; classification is typically based on the responsible enzymatic deficiency and type of lipid involved. Such enzymatic activity takes place in the lysosomes, and the abnormal products appear as lysosomal storage diseases. Sphingolipidoses make up the largest portion of recognized lipidoses, including abnormal metabolism of gangliosides, ceramides, and cerebrosides. [lipid + G. -osis, condition]
ceramide lactoside l. an inherited disorder associated with an accumulation of ceramide lactoside due to a deficiency of ceramide lactosidase; results in progressive brain damage with liver and spleen enlargement.
cerebral l. SYN: cerebral sphingolipidosis.
cerebroside l. SYN: Gaucher disease.
ganglioside l. SYN: gangliosidosis.
glycolipid l. SYN: Fabry disease.
sphingomyelin l. SYN: Niemann-Pick disease.
sulfatide l. SYN: metachromatic leukodystrophy.

Lipmann
Lipmann

Fritz A., German-U.S. biochemist in the U.S. and Nobel laureate, 1899–1986. See Warburg-L.-Dickens-Horecker shunt.

lipo- lipo-, lip-

Fatty, lipid. [G. lipos, fat]

lipoamide
lipoamide (lip-o-am′id, -am′id)

See lipoic acid.

lipoamide dehydrogenase
lipoamide dehydrogenase

SYN: dihydrolipoamide dehydrogenase.

lipoamide disulfide
lipoamide disulfide

Oxidized lipoic acid in amide combination with the ε-amino group of an l-lysyl residue of pyruvic acid dehydrogenase.

lipoamide reductase (NADH)
lipoamide reductase (NADH)

SYN: dihydrolipoamide dehydrogenase.

lipoarthritis
lipoarthritis (lip′o-ar-thri′tis)

Inflammation of the periarticular fatty tissues of the knee. [lipo- + arthritis]

lipoate
lipoate (lip′o-at)

A salt or ester of lipoic acid.

lipoate acetyltransferase
lipoate acetyltransferase

SYN: dihydrolipoamide S-acetyltransferase.

lipoatrophia
lipoatrophia (lip′o-a-tro′fe-a)

SYN: lipoatrophy.
l. annularis a rare condition of unknown cause characterized by localized panatrophy, a depressed area encircling the arm with sclerosis and atrophy of fat.
l. circumscripta localized fat atrophy.

lipoatrophy
lipoatrophy (lip-o-at′ro-fe)

Loss of subcutaneous fat, which may be total, congenital, and associated with hepatomegaly, excessive bone growth, and insulin-resistant diabetes. SYN: Lawrence-Seip syndrome, lipoatrophia, lipoatrophic diabetes. [G. lipos, fat, + a-, priv. + trophe, nourishment]
insulin l. SYN: insulin lipodystrophy.
partial l. SYN: progressive lipodystrophy.

lipoblast
lipoblast (lip′o-blast)

An embryonic fat cell. [lipo- + G. blastos, germ]

lipoblastoma
lipoblastoma (lip′o-blas-to′ma)

A benign subcutaneous tumor composed of embryonal fat cells separated into distinct lobules, occurring usually in infants.

lipoblastomatosis
lipoblastomatosis (lip′o-blas-to-ma-to′sis)

A diffuse form of lipoblastoma that infiltrates locally but does not metastasize.

lipocardiac
lipocardiac (lip′o-kar′de-ak)

1. Relating to fatty heart. 2. Denoting a person suffering from fatty degeneration of the heart. [lipo- + G. kardia, heart]

lipocatabolic
lipocatabolic (lip′o-kat-a-bol′ik)

Relating to the breakdown (catabolism) of fat.

lipoceratous
lipoceratous (lip-o-ser′a-tus)

SYN: adipoceratous.

lipocere
lipocere (lip′o-ser)

SYN: adipocere. [lipo- + L. cera, wax]

lipochondria
lipochondria (lip′o-kon′dre-a)

Temporary storage vacuoles of lipids found in the Golgi apparatus. SEE ALSO: phytosterolemia. [lipo- + mitochondria]

lipochondrodystrophy
lipochondrodystrophy (lip′o-kon-dro-dis′tro-fe)

SYN: Hurler syndrome.

lipochrome
lipochrome (lip′o-krom)

1. A pigmented lipid, e.g., lutein, carotene. SYN: chromolipid. 2. A term sometimes used to designate the wear-and-tear pigments, e.g., lipofuscin, hemofuscin, ceroid. More precisely, lipochromes are yellow pigments that seem to be identical to carotene and xanthophyll and are frequently found in the serum, skin, adrenal cortex, corpus luteum, and arteriosclerotic plaques, as well as in the liver, spleen, and adipose tissue; lipochromes do not stain with the ordinary dyes for fat. 3. The pigment produced by certain bacteria. [lipo- + G. chroma, color]

lipoclasis
lipoclasis (li-pok′la-sis)

SYN: lipolysis. [lipo- + G. klasis, a breaking]

lipoclastic
lipoclastic (lip-o-klas′tik)

SYN: lipolytic.

lipocrit
lipocrit (lip′o-krit)

An apparatus and procedure for separating and volumetrically analyzing the amount of lipid in blood or other body fluid. [lipo- + G. krino, to separate]

lipocyte
lipocyte (lip′o-sit)

SYN: fat-storing cell. [lipo- + G. kytos, cell]

lipodermoid
lipodermoid (lip-o-der′moyd)

Congenital, yellowish-white, fatty, benign tumor located subconjunctivally. [lipo- + dermoid]

lipodieresis
lipodieresis (lip′o-di-er′e-sis)

SYN: lipolysis. [lipo- + G. diairesis, division]

lipodystrophia
lipodystrophia (lip′o-dis-tro′fe-a)

SYN: lipodystrophy.
l. progessiva superior SYN: progressive lipodystrophy.

lipodystrophy
lipodystrophy (lip-o-dis′tro-fe)

Defective metabolism of fat. SYN: lipodystrophia. [lipo- + G. dys-, bad, difficult, + trophe, nourishment]
congenital total l. [MIM*269700] characterized by almost complete lack of subcutaneous fat, accelerated rate of growth and skeletal development during the first 3–4 years of life, muscular hypertrophy, cardiac enlargement, hepatosplenomegaly, acanthosis nigricans, hypertrichosis, renal enlargement, hypertriglyceridemia, and hypermetabolism; autosomal recessive inheritance. SYN: Berardinelli syndrome, Seip syndrome.
familial partial l. [MIM*151660] characterized by symmetric lipoatrophy of the trunk and limbs but the face is spared; with full rounded face, xanthomata, acanthosis nigricans, and insulin-resistant hyperglycemia; there is accumulation of fat around the neck and shoulders and genitalia. SYN: Kobberling-Dunnigan syndrome.
insulin l. dystrophic atrophy of subcutaneous tissues in diabetics at the site of frequent injections of insulin. SYN: insulin lipoatrophy.
membranous l. a rare metabolic disease in which bone marrow fat cells are transformed into thick convoluted PAS-staining membranes enclosing weakly osmophilic material; leads to progressive cystic resorption of limb bones and dementia with sudanophilic leukodystrophy.
progressive l. a condition characterized by a complete loss of the subcutaneous fat of the upper part of the torso, the arms, neck, and face, sometimes with an increase of fat in the tissues about and below the pelvis. SYN: Barraquer disease, lipodystrophia progessiva superior, partial lipoatrophy, Simons disease.

lipoedema
lipoedema (lip′o-e-de′ma)

Edema of subcutaneous fat, causing painful swellings, especially of the legs in women. SYN: cellulite (2) .

lipofectin
lipofectin (lip′o-fek′tin)

A mixture predominantly of phospholipids used for aiding in the transfer of DNA into cells.

lipofection
lipofection (lip′o-fek′shun)

The process of injecting a lipid-complexed or contained DNA into eucaryotic cells. [lipo- + transfection]

lipoferous
lipoferous (lip-of′er-us)

Transporting fat. [lipo- + L. fero, to carry]

lipofibroma
lipofibroma (lip′o-fi-bro′ma)

A benign neoplasm of fibrous connective tissue, with conspicuous numbers of adipose cells.

lipofuscin
lipofuscin (lip-o-fus′in)

Brown pigment granules representing lipid-containing residues of lysosomal digestion and considered one of the aging or “wear and tear” pigments; found in liver, kidney, heart muscle, adrenal, and ganglion cells.

lipofuscinosis
lipofuscinosis (lip′o-fus-i-no′sis)

Abnormal storage of any one of a group of fatty pigments.
ceroid l. SYN: Batten disease.
neuronal ceroid l. a group of diseases characterized by accumulation of abnormal pigments in tissue (previously classified as cerebral sphingolipidoses). Major subtypes include chronic juvenile form (Batten disease), slowly progressive behavior and visual symptoms, autosomal recessive inheritance; acute, late infantile form (Bielschowsky disease); autosomal recessive inheritance; chronic adult form (Kufs disease), variable inheritance; acute infantile form (Santavuori-Haltia disease), fulminating motor and mental deterioration often associated with myoclonic seizures. Minor forms have also been described.

lipogenesis
lipogenesis (lip-o-jen′e-sis)

The production of fat, either fatty degeneration or fatty infiltration; also applied to the normal deposition of fat or to the conversion of carbohydrate or protein to fat. SYN: adipogenesis. [lipo- + G. genesis, production]

lipogenic
lipogenic (lip-o-jen′ik)

Relating to lipogenesis. SYN: adipogenic, adipogenous, lipogenous.

lipogenous
lipogenous (li-poj′e-nus)

SYN: lipogenic.

lipogranuloma
lipogranuloma (lip′o-gran-u-lo′ma)

A nodule or focus of granulomatous inflammation (usually of the foreign-body type) in association with lipid material deposited in tissues, e.g., after the injection of certain oils. SEE ALSO: paraffinoma. SYN: eleoma, oil tumor, oleogranuloma, oleoma.

lipogranulomatosis
lipogranulomatosis (lip′o-gran′u-lo-ma-to′sis)

1. Presence of lipogranulomas. 2. Local inflammatory reaction to necrosis of adipose tissue.
disseminated l. a form of mucolipodosis, developing soon after birth because of deficiency of ceramidase; characterized by swollen joints, subcutaneous nodules, lymphadenopathy, and accumulation in lysosomes of affected cells of PAS-positive lipid consisting of ceramide. SYN: Farber disease, Farber syndrome.

lipohemia
lipohemia (lip-o-he′me-a)

Obsolete term for lipemia.

lipoic acid
lipoic acid (li-po′ik)

Functions as the amide (lipoamide) in the disulfide (–S–S–) form in the transfer of “active aldehyde” (acetyl), the two-carbon fragment resulting from decarboxylation of pyruvate from α-hydroxyethylthiamin pyrophosphate to acetyl-CoA, itself being reduced to the dithiol form ( i.e., dihydrolipoic acid) in the process; present in yeast and liver extracts, and may be useful in the treatment of mushroom poisoning. L. is also an essential component of other α-keto acid dehydrogenase complexes. SYN: acetate replacement factor, ovoprotogen, protogen, protogen A, pyruvate oxidation factor, thioctic acid.

lipoid
lipoid (lip′oyd)

1. Resembling fat. 2. Former term for lipid. SYN: adipoid. [lipo- + G. eidos, appearance]

lipoidemia
lipoidemia (lip-oy-de′me-a)

SYN: lipemia.

lipoidosis
lipoidosis (lip-oy-do′sis)

Presence of anisotropic lipoids in the cells.
cerebroside l. (ser-e′bro-sid) a group of lysosomal storage diseases characterized by accumulation of lipid in cells of affected tissue and commonly accompanied by a manifest derangement of central nervous system development; e.g., Gaucher disease and Krabbe disease.
l. corneae SYN: arcus senilis.
l. cutis et mucosae SYN: lipoid proteinosis.
galactosylceramide l. SYN: globoid cell leukodystrophy.

lipoinjection
lipoinjection (lip-o-in-jek′shun)

Augmentation of tissue with fat cells after atrophy, as in vocal cord paralysis or scarring.

lipolipoidosis
lipolipoidosis (lip′o-lip-oy-do′sis)

Fatty infiltration, both neutral fats and anisotropic lipoids being present in the cells. SEE ALSO: liposis (2) .

lipolysis
lipolysis (li-pol′i-sis)

The splitting up (hydrolysis), or chemical decomposition, of fat. SYN: lipoclasis, lipodieresis. [lipo- + G. lysis, dissolution]

lipolytic
lipolytic (lip-o-lit′ik)

Relating to or causing lipolysis. SYN: lipoclastic.

lipoma
lipoma (li-po′ma)

A benign neoplasm of adipose tissue, composed of mature fat cells. SYN: adipose tumor. [lipo- + G. -oma, tumor]
l. annulare colli an encircling growth of l. (or coalescent lipomas) in the neck, resulting in a collar-like enlargement. SEE ALSO: Madelung neck.
l. arborescens an irregularly shaped l. involving the synovial membrane of a joint, resulting in fingerlike or treelike hyperplastic folds in the villi.
atypical l. l., occurring primarily in older men on the posterior neck, shoulders, and back, which is benign but microscopically atypical, containing giant cells with multiple overlapping nuclei forming a circle. SYN: pleomorphic l..
l. capsulare a well-circumscribed mass resulting from a greatly increased amount of adipose tissue adjacent to the breast.
l. cavernosum SYN: angiolipoma.
l. fibrosum SYN: fibrolipoma.
l. myxomatodes SYN: myxolipoma.
l. ossificans a l. in which metaplasia occurs and small foci of bone are formed.
l. petrificans a l. in which degeneration and necrosis results in a considerable amount of dystrophic calcification.
pleomorphic l. SYN: atypical l..
spindle cell l. a microscopically distinctive benign form of l. in which adipose tissue is infiltrated by fibroblasts and collagen; usually found in the shoulder or neck of elderly men.
telangiectatic l. SYN: angiolipoma.

lipomatoid
lipomatoid (li-po′ma-toyd)

Resembling a lipoma, frequently said of accumulations of adipose tissue that is not thought to be neoplastic.

lipomatosis
lipomatosis (lip′o-ma-to′sis)

SYN: adiposis.
encephalocraniocutaneous l. a rare syndrome of multiple fibrolipomas or angiofibromas of the face, scalp, and neck present at birth, sometimes with symptomatic intracranial lipomas.
mediastinal l. increased mediastinal fat caused by taking steroids.
multiple symmetric l. accumulation and progressive enlargement of collections of adipose tissue in the subcutaneous tissue of the head, neck, upper trunk, and upper portions of the upper extremities; seen primarily in adult males and of unknown cause. SYN: Launois-Bensaude syndrome, Madelung disease, symmetric adenolipomatosis.
l. neurotica SYN: adiposis dolorosa.

lipomatous
lipomatous (li-po′ma-tus)

Pertaining to or manifesting the features of lipoma, or characterized by the presence of a lipoma (or lipomas).

lipomeningocele
lipomeningocele (lip′o-me-ning′go-sel)

An intraspinal cauda equinal lipoma associated with a spina bifida. [lipo- + G. meninx, membrane, + kele, tumor]

lipomucopolysaccharidosis
lipomucopolysaccharidosis (lip′o-mu′ko-pol-e-sak′a-ri-do′sis)

SYN: mucolipidosis I.

liponucleoproteins
liponucleoproteins (lip′o-noo′kle-o-pro′tenz)

Associations or complexes containing lipids, nucleic acids, and proteins.

Liponyssus
Liponyssus (lip-o-nis′us)

Former name for Ornithonyssus. [lipo- + G. nysso, to prick]

lipopenia
lipopenia (lip-o-pe′ne-a)

An abnormally small amount, or a deficiency, of lipids in the body. [lipo- + G. penia, poverty]

lipopenic
lipopenic (lip-o-pe′nik)

1. Relating to or characterized by lipopenia. 2. An agent or drug that produces a reduction in the concentration of lipids in the blood.

lipopeptid
lipopeptid, lipopeptide (lip-o-pep′tid, lip-o-pep′tid)

A compound or complex of lipid and amino acids.

lipophage
lipophage (lip′o-faj)

A cell that ingests fat. [G. lipos, fat, + phago, to eat]

lipophagic
lipophagic (lip-o-fa′jik)

Relating to lipophagy.

lipophagy
lipophagy (lip-of′a-je)

Ingestion of fat by a lipophage. [lipo- + G. phago, to eat]

lipophanerosis
lipophanerosis (lip′o-fan-er-o′sis)

A change in certain cells whereby previously invisible fat becomes demonstrable as small sudanophilic droplets. See fatty degeneration. [lipo- + G. phaneros, visible, + -osis, condition]

lipophil
lipophil (lip′o-fil)

A substance with lipophilic (hydrophobic) properties. [lipo- + G. philos, fond of]

lipophilic
lipophilic (lip-o-fil′ik)

Capable of dissolving, of being dissolved in, or of absorbing lipids.

lipophosphodiesterase I
lipophosphodiesterase I (lip′o-fos′-fo-di-es′ter-as)

SYN: phospholipase C.

lipophosphodiesterase II
lipophosphodiesterase II

SYN: phospholipase D.

lipopolysaccharide
lipopolysaccharide (LPS) (lip′o-pol′e-sak′a-rid)

1. A compound or complex of lipid and carbohydrate. 2. The l. (endotoxin) released from the cell walls of Gram-negative organisms that produces septic shock.

lipoprotein
lipoprotein (lip-o-pro′ten, li-po-)

Any complex or compound containing both lipid and protein. Lipoproteins are important constituents of biological membranes and of myelin. Conjugation with protein facilitates transport of lipids, which are hydrophobic, in the aqueous medium of the plasma. Plasma lipoproteins can be separated by ultracentrifugation, electrophoresis, or immunoelectrophoresis; they migrate electrophoretically with α- and β-globulins, but are usually classified according to their densities (flotation constants). The principal classes by density are chylomicrons, which transport dietary cholesterol and triglycerides from the intestine to the liver and other tissues; very low density lipoproteins (VLDL), which transport triglycerides from intestine and liver to muscle and adipose tissue; low density lipoproteins (LDL), which transport cholesterol to tissues other than the liver; and high density lipoproteins (HDL), which transport cholesterol to the liver for excretion in bile. The properties of these and other plasma lipoproteins are set forth in the accompanying table. The protein moiety of a l. is called an apolipoprotein (or apoprotein). Besides rendering lipids soluble, some apolipoproteins perform biochemical functions such as enzyme activation. The apolipoproteins of plasma lipoproteins are synthesized by the liver and intestinal mucosal cells and vary in molecular weight from 7000 to 500,000. Protein makes up more than 50% of some HDLs but only 1% of chylomicrons. As the proportion of lipid in a l. increases, its density decreases. A plasma l. particle is typically spherical, with a hydrophobic core of triacylglycerol, cholesteryl esters, and apolar amino acid residues surrounded by hydrophilic protein structures and phospholipids.The concentrations of certain serum lipoproteins correlate closely with the risk of atherosclerosis. An HDL cholesterol level below 35 mg/dL (0.90 mmol/L), an LDL cholesterol level above 160 mg/dL (4.15 mmol/L), and a fasting triglyceride level above 250 mg/dL are all independent risk factors for coronary artery disease. Although dietary factors are important in some persons, basal levels of l., cholesterol, and triglycerides depend chiefly on heredity. Several phenotypes of familial hyperlipoproteinemia associated with risk of premature cardiovascular disease and death have been identified. see hyperlipoproteinemia. Medical management of patients with coronary artery disease (myocardial infarction, angina pectoris, history of coronary artery bypass graft or coronary angioplasty) and other atherosclerotic disorders (peripheral arterial disease, abdominal aortic aneurysm, carotid artery disease) includes detection and correction of hypercholesterolemia and hyperlipoproteinemia. Reducing elevated LDL cholesterol diminishes the risk of coronary artery disease; besides halting the progression of atherosclerosis, it may even shrink established atherosclerotic lesions. Of persons with elevated LDL cholesterol, 75% can achieve normal levels with diet, weight reduction, and exercise; the remainder need drug treatment. Factors besides familial hyperlipoproteinemias that can elevate LDL cholesterol include diabetes mellitus, hypothyroidism, nephrotic syndrome, obstructive liver disease, and drugs (progestogens, anabolic steroids, corticosteroids, thiazide diuretics). Dietary saturated fat raises LDL cholesterol more than any other dietary component, cholesterol itself not excepted.
l. (a) a l. consisting of an LDL particle to which a large glycoprotein, apolipoprotein (a), is covalently bonded. Elevation of the concentration in serum has been identified as a risk factor for coronary artery disease.Elevation of plasma l. (a) above 30 mg/dL is a strong independent risk factor for coronary artery disease and possibly for stroke. A unique feature of l. (a) is the structural similarity of its nonlipid moiety, apolipoprotein (a), to plasminogen. This similarity allows it to bind to endothelium and to proteins of cellular membranes. It inhibits fibrinolysis by competing for plasminogen binding sites and also favors lipid deposition and stimulates smooth muscle cell proliferation. Niacin and estrogen lower Lp(a), but HMG-CoA reductase inhibitors, fibrates, and bile acid sequestrants do not.
α₁-l. A l. fraction of relatively low molecular weight, high density, rich in phospholipids, and found in the α₁-globulin fraction of human plasma.
β₁-l. A l. fraction of relatively high molecular weight, low density, rich in cholesterol, and found in the β-globulin fraction of human plasma.
intermediate density l. (IDL) class of lipoproteins formed in degradation of very low density lipoproteins; about half are cleared quickly from the plasma into the liver by receptor-mediated endocytosis; the other half are degraded into low density lipoproteins.
l. Lp(a) a l. composed of an LDL particle combined with an additional protein, Lp(a) specific protein; elevated levels have been identified as a risk factor for coronary artery disease; elevations may be treated with niacin.
malondialdehyde-modified low-density l. lDL molecule with aldehyde-substituted lysine residue(s) in the apoprotein moiety, resulting from oxidative reaction accompanying prostaglandin synthesis and platelet aggregation.
l.-X An abnormal low-density l. found in patients with obstructive jaundice.

lipoprotein lipase
lipoprotein lipase

An enzyme that hydrolyzes one fatty acid from a triacylglycerol; its activity is enhanced by heparin and inactivated by heparinase. It is activated by apolipoprotein C-II; a deficiency of l. is associated with familial hyperlipoproteinemia type I. SEE ALSO: familial l. inhibitor, clearing factors, under factor. SYN: diacylglycerol lipase, diglyceride lipase.

liposarcoma
liposarcoma (lip′o-sar-ko′ma)

A malignant neoplasm of adults that occurs especially in the retroperitoneal tissues and the thigh, usually deep in the intermuscular or periarticular planes; histologically, l. is a large tumor that may be composed of well-differentiated fat cells or may be dedifferentiated, either myxoid, round-celled, or pleomorphic, usually in association with a rich network of capillaries; recurrences are common, and dedifferentiated l. metastasizes to the lungs or serosal surfaces. [lipo- + sarx, flesh, + -oma, tumor]

liposis
liposis (li-po′sis)

1. SYN: adiposis. 2. Fatty infiltration, neutral fats being present in the cells. SEE ALSO: lipolipoidosis. [lipo- + G. -osis, condition]

lipositol
lipositol (lip-os′i-tol)

SYN: inositol.

liposoluble
liposoluble (lip-o-sol′u-bl)

Fat-soluble.

liposome
liposome (lip′o-som)

1. A spherical particle of lipid substance suspended in an aqueous medium within a tissue. 2. Any small, roughly spherical artificial vesicle consisting of a lipid bilayer enclosing some of the suspending medium. [lipo- + G. soma, body]

liposuction
liposuction (lip′o-suk-shun)

Method of removing unwanted subcutaneous fat using percutaneously placed suction tubes.
tumescent l. l. performed after subcutaneous infusion of lidocaine solution and the use of microcannulae.
wet-technique l. l. performed after subcutaneous infusion of dilute epinephrine solution.

liposuctioning
liposuctioning (lip′o-suk′shun-ing)

Removal of fat by high vacuum pressure; used in body contouring.

lipothiamide pyrophosphate
lipothiamide pyrophosphate (lip-o-thi′am-id)

Name once given to the coenzymes of the multienzyme complex catalyzing the formation of acetyl-CoA from pyruvate and involving lipoamide and thiamin pyrophosphate, on the assumption that they were a single compound. See lipoic acid.

lipotrophic
lipotrophic (lip-o-trof′ik)

Relating to lipotrophy.

lipotrophy
lipotrophy (li-pot′ro-fe)

An increase of fat in the body. [lipo- + G. trophe, nourishment]

lipotropic
lipotropic (lip-o-trop′ik)

1. Pertaining to substances preventing or correcting excessive fat deposits in liver such as occurs in choline deficiency. 2. Relating to lipotropy.

lipotropin
lipotropin (li-po-tro′pin)

A pituitary hormone mobilizing fat from adipose tissue. β-L. is a single-chain peptide of 91 amino acyl residues that contains the sequences of endorphins, metenkephalin, and β-melanotropin; γ-l. is shorter and is identical in sequence to the N-terminal 58 residues of β-l.; both contain sequences common to ACTH and β-melanotropin. SYN: lipid-mobilizing hormone, lipotropic hormone, lipotropic pituitary hormone.

lipotropy
lipotropy (li-pot′ro-pe)

1. Affinity of basic dyes for fatty tissue. 2. Prevention of accumulation of fat in the liver. 3. Affinity of nonpolar substances for each other. [lipo- + G. trope, turning]

lipovaccine
lipovaccine (lip′o-vak-sen)

A vaccine suspended in vegetable oil as a solvent. See adjuvant vaccine.

lipovitellin
lipovitellin (lip′o-vi-tel′in)

SYN: vitellin.

lipoxenous
lipoxenous (li-pok′se-nus)

Pertaining to lipoxeny.

lipoxeny
lipoxeny (li-pok′se-ne, li-)

Desertion of the host by a parasite when the development of the latter is complete. [G. leipo, to leave, + xenos, host]

lipoxidase
lipoxidase (li-poks′i-das)

SYN: lipoxygenase.

lipoxygenase
lipoxygenase (li-poks′e-je-nas)

A class of enzymes that catalyzes the oxidation of unsaturated fatty acids with O₂ to yield hydroperoxides of the fatty acids; 5-l. catalyzes the first step in leukotriene biosynthesis, acting on arachidonate. SYN: carotene oxidase, lipoxidase.

lipoyl
lipoyl (lip′o-il)

The acyl radical of lipoic acid.

lipoyl dehydrogenase
lipoyl dehydrogenase

SYN: dihydrolipoamide dehydrogenase.

lipping
lipping (lip′ing)

The formation of a liplike structure, as at the articular end of a bone in osteoarthritis.

lippitude
lippitude, lippitudo (lip′i-tood, lip-i-too′do)

SYN: blear eye. [L., fr. lippus, blear-eyed]

Lipschütz
Lipschütz

Benjamin, Austrian physician, 1878–1931. See L. cell.

lipuria
lipuria (li-poo′re-a)

Presence of lipids in the urine. SYN: adiposuria. [lipo- + G. ouron, urine]

lipuric
lipuric (li-poo′rik)

Pertaining to lipuria.

liquefacient
liquefacient (lik′we-fa′shent)

1. Making liquid; causing a solid to become liquid. 2. Denoting a resolvant supposed to cause the resolution of a solid tumor by liquefying its contents. [L. lique-facio, pres. p. -faciens, to make fluid, fr. liqueo, to be liquid]

liquefaction
liquefaction (lik-we-fak′shun)

The act of becoming liquid; change from a solid to a liquid form. [see liquefacient]

liquefactive
liquefactive (lik-we-fak′tiv)

Relating to liquefaction.

liqueur
liqueur (li-ker′)

A cordial; a spirit containing sugar and aromatics. [Fr.]

liquid
liquid (l) (lik′wid)

1. An inelastic substance, like water, that is neither solid nor gaseous and in which the molecules are relatively free to move with respect to each other yet still are restricted by intermolecular forces. 2. Flowing like water. [L. liquidus]
Cotunnius l. SYN: perilymph.

liquor
liquor, gen. liquoris, pl .liquores (lik′er, -wor-is, -wo′res) [TA]

1. Any liquid or fluid. 2. A term used for certain body fluids. 3. The pharmacopoeial term for any aqueous solution (not a decoction or infusion) of a nonvolatile substance and for aqueous solutions of gases. SEE ALSO: solution. [L.]
l. amnii SYN: amnionic fluid.
l. cerebrospinalis [TA] SYN: cerebrospinal fluid.
l. cotunnii SYN: perilymph.
l. entericus intestinal secretions.
l. folliculi the fluid within the antrum of the ovarian follicle.
malt l. a beverage brewed from malt, such as beer or ale.
Morgagni l. a fluid found postmortem between the epithelium and the fibers of the lens, resulting from the liquefaction of a semifluid material existing there during life. SYN: Morgagni humor.
mother l. the saturated solution remaining after a crystallization or precipitation.
Scarpa l. SYN: endolymph.
spirituous l. a strong alcoholic l. obtained by distillation, such as whiskey.
vinous l. SYN: wine (1) .

liquorice
liquorice (lik′o-ris)

SYN: glycyrrhiza.

liquorrhea
liquorrhea (lik-o-re′a)

The flow of liquid. [L. liquor, fluid, + G. rhoia, flow]

Lisch
Lisch

Karl, Austrian ophthalmologist, *1907. See L. nodule.

Lisfranc
Lisfranc (de St. Martin)

Jacques, French surgeon, 1790–1847. See L. amputation, L. joints, under joint, L. ligaments, under ligament, L. operation, scalene tubercle of L..

lisinopril
lisinopril (lis-in′o-pril)

An angiotensin-converting enzyme inhibitor used in the treatment of hypertension.

Lison
Lison

Lucien, Belgian scientist, *1907. See L.-Dunn stain.

lisping
lisping

Mispronunciation of the sibilants s and z. SYN: parasigmatism, sigmatism.

lissamine rhodamine B 200
lissamine rhodamine B 200 (lis′sa-men ro′da-men)

SYN: sulforhodamine B.

Lissauer
Lissauer

Heinrich, German neurologist, 1861–1891. See L. bundle, L. column, L. fasciculus, L. tract, L. marginal zone, column of Spitzka-L..

lissencephalia
lissencephalia (lis′en-se-fa′le-a)

SYN: agyria. [G. lissos, smooth, + enkephalos, brain]

lissencephalic
lissencephalic (lis′en-se-fal′ik)

Pertaining to, or characterized by, lissencephalia.

lissencephaly
lissencephaly (lis-en-sef′a-le)

SYN: agyria. [G. lissos, smooth, + enkephalos, brain]

lissive
lissive (lis′iv)

Having the property of relieving muscle spasm without causing flaccidity. [G. lissos, smooth]

lissosphincter
lissosphincter (lis′o-sfingk′ter)

A sphincter of smooth musculature. SYN: smooth muscular sphincter. [G. lissos, smooth, + sphincter]

lissotrichic
lissotrichic, lissotrichous (lis-o-trik′ik, -trik′us)

Having straight hair. [G. lissos, smooth, + thrix (trich-), hair]

Lister
Lister

Joseph (Lord L.), English surgeon, 1827–1912. See Listerella, Listeria, listerism, L. dressing, L. method, L. tubercle.

Listerella
Listerella (lis′ter-el′a)

In bacteriology, a rejected generic name sometimes cited as a synonym of Listeria. The type species is L. hepatolytica. [Joseph Lister]

Listeria
Listeria (lis-ter-e-a)

A genus of aerobic to microaerophilic, motile, peritrichous bacteria containing small, coccoid, Gram-positive rods; these organisms tend to produce chains of 3–5 cells and, in the rough state, elongated and filamentous forms. Cells 18–24 hours old may show a palisade arrangement with a few V or Y forms; the bacteria produce acid but no gas from glucose and are found in the feces of humans and other animals, on vegetation, and in silage and are parasitic on poikilothermic and warm-blooded animals, including humans. The type species is L. monocytogenes. [Joseph Lister]
L. denitrificans a bacterial species reclassified as Jonesia denitrificans.
L. grayi a bacterial species found in the feces of chinchillas.
L. monocytogenes a bacterial species causing meningitis, encephalitis, septicemia, endocarditis, abortion, abscesses, and local purulent lesions; it is often fatal; it is found in healthy ferrets, insects, and the feces of chinchillas, ruminants, and humans, as well as in sewage, decaying vegetation, silage, soil, and fertilizer. Sometimes involved in infections in immunocompromised hosts. A causative agent of perinatal infections, neonatal sepsis and septicemia. Also recently linked to food-borne diseases especially associated with meat and dairy products.

listeriosis
listeriosis (lis-ter′e-o′sis)

A sporadic disease of animals and humans, particularly those who are immunocompromised or pregnant, caused by the bacterium, Listeria monocytogenes. The infection in sheep and cattle frequently involves the central nervous system, causing various neurologic signs; in monogastric animals and fowl, the chief manifestations are septicemia and necrosis of the liver. Meningitis, bacteremia, and focal metastatic disease are associated with l.. SYN: listeria meningitis. [fr. organism Listeria]

listerism
listerism (lis′ter-izm)

SYN: Lister method.

Listing
Listing

Johann B., German physiologist, 1808–1882. See L. reduced eye, L. law.

Liston
Liston

Robert, English surgeon, 1794–1847. See L. knives, under knife, L. shears.

lisuride
lisuride (li′soor-id)

A soluble ergot derivative with endocrine effects similar to those of bromocriptine; a serotonin inhibitor.

liter
liter (L, l) (le′ter)

A measure of capacity of 1000 cubic centimeters or 1 cubic decimeter; equivalent to 1.056688 quarts (U.S., liquid). [Fr., fr. G. litra, a pound]

literature
literature

gray l. reports containing data, e.g., on health and disease in a population, that are unpublished or have limited distribution. Examples include local health department reports and masters' and doctoral dissertations lodged in university libraries.

lith- lith-

See litho-.

lithagogue
lithagogue (lith′a-gog)

Causing the dislodgment or expulsion of calculi, especially urinary calculi. [litho- + G. agogos, drawing forth]

litharge
litharge (lith′arj)

SYN: lead monoxide. [litho- + G. argyros, silver]

lithectomy
lithectomy (li-thek′to-me)

SYN: lithotomy. [litho- + G. ektome, excision]

lithiasis
lithiasis (li-thi′a-sis)

Formation of calculi of any kind, especially of biliary or urinary calculi. [litho- + G. -iasis, condition]
l. conjunctivae hard nodules caused by deposition of calcareous material in areas of cellular degeneration in Henle glands.
2,8-dihydroxyadenine l. formation of calculi of 2,8-dihydroxyadenine due to a deficiency or reduced activity of adenine phosphoribosyltransferase.
pancreatic l. the formation of stones in the pancreas, usually associated with chronic inflammation and obstruction of the pancreatic ducts.

lithic acid
lithic acid (lith′ik)

SYN: uric acid.

lithium
lithium (Li) (lith′e-um)

An element of the alkali metal group, atomic no. 3, atomic wt. 6.941. Many of its salts have clinical applications. [Mod. L. fr. G. lithos, a stone]
l. bromide LiBr;a white deliquescent powder, used as a sedative and hypnotic.
l. carbonate an antirheumatic and antilithic agent, also used in the treatment and prophylaxis of depressive, hypomanic, and manic phases of bipolar affective disorders.
l. citrate a diuretic and antirheumatic, also used in the treatment of manic psychosis.
effervescent l. citrate a preparation containing l. citrate, sodium bicarbonate, tartaric acid, and citric acid; same use as potassium or sodium citrate.
l. tungstate used in electron microscopy as a negative stain.

litho- litho-, lith-

A stone, calculus, calcification. [G. lithos]

Lithobius
Lithobius (li-tho′be-us)

A genus of centipedes characterized by 15 pairs of legs. Species common in the U.S. include L. multidentatus and L. forficatus. [litho- + G. bios, life]

lithocholic acid
lithocholic acid (lith-o-ko′lik)

One of the acids isolated from human bile as well as from that of cows, rabbits, sheep, and goats.

lithoclast
lithoclast (lith′o-klast)

SYN: lithotrite. [litho- + G. klastos, broken]

lithogenesis
lithogenesis, lithogeny (lith-o-jen′e-sis, lith-oj′e-ne)

Formation of calculi. [litho- + G. genesis, production]

lithogenic
lithogenic (lith-o-jen′ik)

Promoting the formation of calculi.

lithogenous
lithogenous (lith-oj′e-nus)

Calculus-forming.

lithoid
lithoid (lith′oyd)

Resembling a calculus or stone. [litho- + G. eidos, resemblance]

lithokelyphopedion
lithokelyphopedion, lithokelyphopedium (lith-o-kel′e-fo-pe′de-on, -um)

A lithopedion in which the fetal parts in contact with the surrounding membranes, as well as the membranes, are calcified. [litho- + G. kelyphos, husk, shell, + paidion, child]

lithokelyphos
lithokelyphos (lith-o-kel′e-fos)

A type of lithopedion in which the fetal membranes alone undergo calcification. [litho- + G. kelyphos, rind, shell]

litholabe
litholabe (lith′o-lab)

Obsolete instrument for holding a bladder calculus during its removal. [litho- + G. lambano, labein, to grasp]

litholapaxy
litholapaxy (li-thol′a-pak-se)

The technique of crushing a stone in the bladder and washing out the fragments through a catheter. [litho- + G. lapaxis, an emptying out]

litholysis
litholysis (li-thol′i-sis)

The dissolution of urinary calculi. [litho- + G. lysis, dissolution]

litholyte
litholyte (lith′o-lit)

An instrument for injecting calculary solvents.

litholytic
litholytic (li-tho-lit′ik)

1. Tending to dissolve calculi. 2. An agent having such properties. [litho- + G. lysis, dissolution]

lithomyl
lithomyl (lith′o-mil)

An instrument for pulverizing a stone in the bladder. [litho- + G. myle, mill]

lithonephritis
lithonephritis (lith′o-ne-fri′tis)

Interstitial nephritis associated with calculus formation.

lithopedion
lithopedion, lithopedium (lith-o-pe′de-on, -um)

A retained fetus, usually extrauterine, that has become calcified. [litho- + G. paidion, small child]

lithotome
lithotome (lith′o-tom)

A knife used in lithotomy.

lithotomist
lithotomist (li-thot′o-mist)

A person skilled in lithotomy.

lithotomy
lithotomy (li-thot′o-me)

Cutting for stone; a cutting operation for the removal of a calculus, especially a vesical calculus. SYN: lithectomy. [litho- + G. tome, incision]
high l. SYN: suprapubic l..
lateral l. l. in which the perineum is incised to one side of the median line.
marian l. SYN: median l.. [L. mas (mar-), male]
median l. l. in which the perineal incision is made in the median raphe. SYN: marian l..
perineal l. l. in which the bladder is approached by an incision in the perineum.
prerectal l. l. by an incision in the midline of the perineum anterior to anus.
suprapubic l. l. in which the bladder is entered by an incision immediately above the symphysis pubis. SYN: high l..
vaginal l. l. in which the bladder or ureter is entered through an incision in the vagina.
vesical l. SYN: cystolithotomy.

lithotresis
lithotresis (lith-o-tre′sis)

The boring of holes in a calculus to facilitate its crushing. [litho- + G. tresis, a boring]

lithotripsy
lithotripsy (lith′o-trip-se)

The crushing of a stone in the renal pelvis, ureter, or bladder, by mechanical force or focused sound energy. SYN: lithotrity. [litho- + G. tripsis, a rubbing]
electrohydraulic shock wave l. (ESWL) destruction of calculi (urinary tract or other) by fragmentation using shock waves sent transcutaneously via ultrasound transducers.
extracorporeal shock wave l. (ESWL) (lith′o-trip′se) breaking up of renal or ureteral calculi by focused sound energy.
shock wave l. a method of fragmenting calculi.
ultrasonic l. the demolition of calculi by high frequency sound waves.

lithotriptic
lithotriptic (lith-o-trip′tik)

1. Relating to lithotripsy. 2. An agent that effects the dissolution of a calculus.

lithotriptor
lithotriptor (lith-o-trip′tor)

A device used to crush or fragment a calculus in lithotripsy.

lithotriptoscopy
lithotriptoscopy (lith′o-trip-tos′ko-pe)

Crushing of a stone in the bladder under direct vision by use of a lithotriptoscope. [litho- + G. tribo, to rub, crush, + skopeo, to view]

lithotrite
lithotrite (lith′o-trit)

A mechanical instrument used to crush a urinary calculus in lithotripsy. SYN: lithoclast. [litho- + L. tero, pp. tritus, to rub]

lithotrity
lithotrity (li-thot′ri-te)

SYN: lithotripsy.

lithotroph
lithotroph (lith′o-trof)

An organism whose carbon needs are satisfied by carbon dioxide. Cf.:chemoautotroph.

lithuresis
lithuresis (lith′u-re′sis)

The passage of gravel in the urine. [litho- + G. ouresis, urination]

lithuria
lithuria (li-thoo′re-a)

Excretion of uric acid or urates in large amount in the urine. [lithic (acid) + G. ouron, urine]

litmus
litmus (lit′mus) [old C.I. 1242]

A blue coloring matter obtained from Roccella tinctoria and other species of lichens, the principal component of which is azolitmin; used as an indicator (reddened by acids and turned blue again by alkalies). [a corruption of lacmus, fr. Dutch lakmoes]

litter
litter (lit′er)

1. A stretcher or portable couch for moving the sick or injured. 2. A group of animals of the same parents, born at the same time. SYN: brood (1) . [Fr. litière; fr. lit, bed]

Little
Little

James, U.S. surgeon, 1836–1885. See L. area.

Little
Little

William J., English surgeon, 1810–1894. See L. disease.

Littré
Littré

Alexis, French anatomist, 1658–1726. See Littré glands, under gland, Littré hernia.

Litzmann
Litzmann

Karl K.T., German gynecologist, 1815–1890. See L. obliquity.

livebirth
livebirth, live birth (liv′berth)

The birth of an infant who shows evidence of life after birth. SEE ALSO: liveborn infant.

livedo
livedo (li-ve′do)

A bluish discoloration of the skin, either in limited patches or general. [L. lividness, fr. liveo, to be black and blue]
postmortem l. a purple coloration of dependent parts, except in areas of contact pressure, appearing within one half to two hours after death, as a result of gravitational movement of blood within the vessels. SYN: postmortem hypostasis, postmortem lividity, postmortem suggillation.
l. reticularis a persistent purplish network-patterned discoloration of the skin caused by dilation of capillaries and venules due to stasis or changes in underlying blood vessels including hyalinization; rarely appears as a developmental defect. SYN: dermatopathia pigmentosa reticularis.
l. reticularis idiopathica an extensive and permanent form of l. reticularis; in rare instances associated with central arterial disease.
l. reticularis symptomatica a discoloration or mottling of the skin due to some demonstrable cause, such as seen in erythema ab igne, and in certain tuberculids. SEE ALSO: cutis marmorata.
l. telangiectatica a permanent mottling of the skin due to an anomaly, probably congenital, of the cutaneous capillaries; a form of l. reticularis.

livedoid
livedoid (liv′e-doyd)

Pertaining to or resembling livedo.

liver
liver (liv′er) [TA]

The largest gland of the body, lying beneath the diaphragm in the right hypochondrium and upper part of the epigastric region; it is of irregular shape and weighs from 1–2 kg, or about 140 the weight of the body. As an exocrine gland it secretes bile; it initially receives most absorbed nutrients via the portal vein; it detoxifies and is also of great importance in fat, carbohydrate, and protein metabolism and stores glycogen. SYN: hepar [TA] . [A.S. lifer]
cardiac l. SYN: cardiac cirrhosis.
desiccated l. a dried undefatted powder prepared from mammalian livers used as human food; contains riboflavin, nicotinic acid, and choline; used in the treatment of macrocytic anemias and as a nutritional supplement.
fatty l. yellow discoloration of the l. due to fatty degeneration of l. parenchymal cells. SYN: hepatic steatosis.
hobnail l. in Laënnec cirrhosis, the contraction of scar tissue and hepatic cellular regeneration which causes a nodular appearance of the livers surface.
lardaceous l. SYN: waxy l..
left l. [TA] portion of the l. receiving blood from the left branches of the hepatic artery and portal vein, and from which bile is drained via the left hepatic duct; the plane of the middle hepatic vein (demarcated externally on the visceral surface by the fossae for the gallbladder and inferior vena cava and on the diaphragmatic surface by a line extrapolated from the gallbladder to the terminal inferior vena cava) separates left from right l.. SYN: pars hepatis sinistra [TA] , left part of l.&star.
nutmeg l. chronic passive congestion of the l., causing accentuation of the lobular pattern with red central and yellow or tan periportal zones.
pigmented l. a l. that contains pigment, such as occurs in Dubin-Johnson syndrome, hemochromatosis, long-standing malaria.
polycystic l. gradual cystic dilation of intralobular bile ducts (Meyenburg complexes) that fail to involute in embryologic development of the l.; frequently associated with bilateral congenital polycystic kidneys and occasionally with cystic involvement of the pancreas, lungs, and other organs. SYN: polycystic l. disease.
posterior l. posterior hepatic segment I.
right l. [TA] portion of the l. receiving blood from the right branches of the hepatic artery and portal vein, and from which bile is drained via the right hepatic duct; the plane of the middle hepatic vein (demarcated externally on the visceral surface by the fossae for the gallbladder and inferior vena cava and on the diaphragmatic surface by a line extrapolated from the gallbladder to the terminal inferior vena cava) separates right from left l.. SYN: pars hepatis dextra [TA] , right part of l.&star.
wandering l. SYN: hepatoptosis.
waxy l. amyloid degeneration of the l.. SYN: lardaceous l..

livetin
livetin (liv′e-tin)

Any of the three major water-soluble proteins in egg yolk: α-l., serum albumin; β-l., α-glycoprotein; γ-l., serum γ-globulin.

livid
livid

Having a black and blue or a leaden or ashy gray color, as in discoloration from a contusion, congestion, or cyanosis. [L. lividus, being black and blue]

lividity
lividity (li-vid′i-te)

The state of being livid.
postmortem l. SYN: postmortem livedo.

livor
livor (li′vor)

The livid discoloration of the skin on the dependent parts of a corpse. [L. a black and blue spot]

lixivium
lixivium (lik-siv′e-um)

SYN: lye. [L. ntr. of lixivius, made into lye]

LLAT
LLAT

Abbreviation for lysolecithin-lecithin acyltransferase.

LLETZ
LLETZ

Abbreviation for large loop excision of transformation zone of the cervix of the uterus.

LLL
LLL

Abbreviation for left lower lobe (of lung).

Lloyd
Lloyd

John Uri, U.S. pharmacist, 1849–1936. Noted for investigational work in plant chemistry and phytochemistry as applied to medicines, alkaloids, and glucosides.

Lloyd reagent
Lloyd reagent

See under reagent.

LLQ
LLQ

Abbreviation for left lower quadrant (of abdomen).

LM
LM

Abbreviation for licentiate in midwifery.

lm
lm

Abbreviation for lumen (2) .

LMA
LMA

Abbreviation for left mentoanterior position.

LMP
LMP

1. Abbreviation for left mentoposterior position; last menstrual period; latent membrane protein; low molecular weight proteins, under protein. 2. Gene product of Epstein-Barr virus (latent membrane protein).

LMT
LMT

Abbreviation for left mentotransverse position.

<SMCAP>l</SMCAP>-α-narcotine
l-α-narcotine

SYN: noscapine.

LNPF
LNPF

Abbreviation for lymph node permeability factor.

Lo
Lo, L_o

See L. dose.

LOA
LOA

Abbreviation for left occipitoanterior position.

load
load (lod)

1. A departure from normal body content, as of water, salt, or heat; positive loads are quantities in excess of the normal; negative loads are quantities in deficit. 2. The quantity of a measurable entity borne by an object or organism. [M.E. lode, fr. A.S. lad,]
electronic pacemaker l. the impedance to the output, the standard l. being 500 ohms resistance ± 1%.
genetic l. the aggregate of more or less harmful genes that are carried, mostly hidden, in the genome that may be transmitted to descendants and cause morbidity and disease; in classical genetic dynamics, genetic l. may be seen as undischarged genetic debts that result from previous mutations, each of which is supposed to exact an average number of lethal equivalents dependent only on the pattern of inheritance, regardless of how mild or severe the phenotype may be.
viral l. the plasma level of viral RNA, as determined by various techniques including target amplification assay by reverse transcriptase polymerase chain reaction and branched DNA technology with signal amplification. Because levels of detection vary with method, results of testing by different methods are not comparable.Serial measurement of HIV viral l. has become a standard procedure in monitoring the course of AIDS. Reported as the number of copies of viral RNA per mL of plasma, assessment of viral l. provides important information about the number of lymphoid cells actively infected with HIV. This laboratory procedure has supplanted the CD4 count as an indicator of prognosis of persons infected with HIV, in determining when to start antiretroviral therapy, and in measuring the response to therapy. Because the CD4 count is regarded as superior in determining the level of immune compromise and the risk of opportunistic infection, both tests are currently used. Antiretroviral therapy is started when plasma HIV RNA concentration exceeds 5000 copies/mL. When, as a result of treatment, the number of copies of viral RNA falls below the level that can be detected by standard methods, replication of HIV is considered to have been suppressed. In no case, however, has AIDS been cured, nor has viral proliferation remained arrested after cessation of antiretroviral therapy.

loading
loading (lod′ing)

Administration of a substance for the purpose of testing metabolic function.
carbohydrate l. a procedure, popular with long-distance runners and other athletes, of filling muscles with a large glycogen pool prior to an athletic event; often, the athlete consumes very few carbohydrates for three days, followed by a largely carbohydrate diet for the last three days before the event.
salt l. the administration of 2 g of sodium chloride (with a regular diet) 3 times a day for 4 days; a diagnostic test in primary aldosteronism, in which the salt l. produces a typical plasma electrolyte and hormonal pattern.
soda l. a procedure adopted by a number of athletes of ingesting sodium bicarbonate in an attempt to buffer the production of protons during exercise.

Loa loa
Loa loa (lo′a lo′a)

The African eye worm, a species of the family Onchocercidae (superfamily Filarioidea) that is indigenous to the western part of equatorial Africa, especially in the region of the Congo River, and is the causal agent of loiasis. Adult worms are white or gray-white, cylindroid, and threadlike, the males averaging 25–35 by 0.3–0.4 mm (with a curved tail) and the females ranging from 50–60 by 0.4–0.6 mm; microfilariae are ensheathed, with nuclei extending to the tip of the tail. The life cycle is somewhat similar to that of Wuchereria species; humans are the only known definitive host, and parasites are transmitted by Chrysops flies (family Tabanidae); infective larvae from the latter require 3 years or more to mature in humans, and the adult forms may persist in a human host for as long as 17 years. SEE ALSO: loiasis.

lobar
lobar (lo′bar)

Relating to any lobe.
l. nephronia 1. a focal renal mass related to acute infection. 2. acute focal bacterial nephritis. 3. renal phlegmon (not an abscess; no free pus).

lobate
lobate (lo′bat)

1. Divided into lobes. 2. Lobe-shaped; denoting a bacterial colony with a deeply undulate margin. SYN: lobose, lobous.

lobe
lobe (lob) [TA]

1. One of the subdivisions of an organ or other part, bounded by fissures, sulci, connective tissue septa, or other structural demarcations. 2. A rounded projecting part, as the l. of the ear. SEE ALSO: lobule. 3. One of the larger divisions of the crown of a tooth, formed from a distinct point of calcification. SYN: lobus [TA] . [G. lobos, l.]
anterior l. of hypophysis adenohypophysis.
azygos l. of right lung a small accessory l. sometimes formed above the hilum of the right lung; separated from the rest of the upper l. by a deep groove lodging the azygos vein. SYN: lobus azygos pulmonis dextri.
caudate l. posterior hepatic segment I.
cerebral lobes SYN: lobi cerebri, under lobus.
cuneiform l. SYN: biventer lobule.
ear l. SYN: lobule of auricle.
falciform l. SYN: cingulate gyrus.
flocculonodular l. [TA] the small posterior and inferior subdivision of the cerebellar cortex that borders the line of attachment of the choroid roof of the rhomboid fossa, and consists of the left and right flocculus together with the unpaired nodulus (the most posterior of the folia composing the vermis cerebelli). Its major afferent connections come from the vestibular nuclei and directly from the vestibular nerve; it projects largely to the vestibular nuclei, directly and by way of the fastigial nucleus. SYN: lobus flocculonodularis [TA] .
frontal l. [TA] SYN: frontal l. of cerebrum.
frontal l. of cerebrum [TA] the portion of each cerebral hemisphere anterior to the central sulcus. SYN: frontal l. [TA] , lobus frontalis [TA] .
glandular l. of hypophysis SYN: adenohypophysis.
Home l. the enlarged middle l. of the prostate gland.
inferior l. of (left / right) lung it is located below and behind the oblique fissure and contains five bronchopulmonary segments: superior (S VI), medial basal (S VII), anterior basal (S VIII), lateral basal (S IX), and posterior basal (S X). SYN: lobus inferior pulmonis dextri et sinistri [TA] , lower l. of lung&star.
insular l. lobus insula.
kidney lobes [TA] one of the subdivisions of the kidney, consisting of a renal pyramid and the cortical tissue associated with it. SYN: lobus renalis [TA] , renal l..
left l. [TA] the left subdivision of several glands, e.g., prostate, thyroid, thymus. SYN: lobus sinister [TA] .
left l. of liver [TA] it is separated from the much larger right l. anterior and superior to the falciform and coronary ligaments, and from the quadrate and caudate lobes by the fissure for the ligamentum teres and the fissure for the ligamentum venosum. The lobes of the liver are not functional units, being defined by external structures; the distribution of the portal vein, hepatic artery, and bile ducts does not correspond to the gross lobar divisions of the liver. SYN: lobus hepatis sinister [TA] , divisio lateralis sinistra&star, lateral division of left liver&star.
limbic l. [TA] as originally defined by P. Broca: the nearly closed ring of the brain structures surrounding the hilus, or margin, of the cerebral hemisphere of mammals; it is composed of the fornicate gyrus (cingulate gyrus, fasciolar gyrus, parahippocampal gyrus, and uncus), and the hippocampus. See limbic system. SYN: lobus limbicus [TA] .
lingual l. SYN: cingulum of tooth.
lower l. of lung inferior l. of (left / right) lung.
lobes of mammary gland [TA] the 15–20 separate portions of the mammary gland that radiate from the central area deep to the nipplelike wheel spokes and make up the body of the mammary gland; each is drained by a single lactiferous duct. SYN: lobi glandulae mammariae [TA] .
middle l. of prostate [TA] the portion of the prostate lying between the urethra and the ejaculatory ducts; indistinct unless hypertrophied. SYN: lobus medius prostatae [TA] , Morgagni caruncle.
middle l. of right lung [TA] it is located anteriorly between the horizontal and oblique fissures and includes lateral (S IV) and medial (S V) bronchopulmonary segments. SYN: lobus medius pulmonis dextri [TA] .
nervous l. SYN: neurohypophysis.
neural l. of hypophysis the bulbous part of the neurohypophysis attached to the hypothalamus by the infundibulum. It is composed of pituicytes, blood vessels, and terminals of nerve fibers from the supraoptic and paraventricular nuclei.
occipital l. [TA] SYN: occipital l. of cerebrum.
occipital l. of cerebrum [TA] the posterior, somewhat pyramid-shaped part of each cerebral hemisphere, demarcated by no distinct surface markings on the lateral convexity of the hemisphere from the parietal and temporal lobes, but sharply delineated from the parietal l. by the parieto-occipital sulcus on the medial surface. SYN: lobus occipitalis [TA] , occipital l. [TA] .
parietal l. [TA] SYN: parietal l. of cerebrum.
parietal l. of cerebrum [TA] the middle portion of each cerebral hemisphere, separated from the frontal l. by the central sulcus, from the temporal l. by the lateral sulcus in front and an imaginary line projected posteriorly, and from the occipital l. only partially by the parieto-occipital sulcus on its medial aspect. SYN: lobus parietalis [TA] , parietal l. [TA] .
placental lobes cotyledons of the human placenta, viewed on the maternal surface as irregularly shaped elevations or lobes.
polyalveolar l. a type of congenital anomaly where a severalfold increase in the total alveolar number leads to congenital lobar emphysema.
posterior l. of hypophysis SYN: neurohypophysis.
l. of prostate [TA] one of the lateral lobes (right or left) or the middle l. or isthmus of the prostate; in the adult the lobes are ill-defined. SYN: lobus prostatae [TA] .
pyramidal l. of thyroid gland [TA] an inconstant narrow l. of the thyroid gland that arises from the upper border of the isthmus and extends upward, sometimes as far as the hyoid bone; it marks the point of continuity with the thyroglossal duct. SYN: lobus pyramidalis glandulae thyroideae [TA] , Lallouette pyramid, Morgagni appendix, pyramid of thyroid.
quadrate l. 1. a l. on the inferior surface of the liver located between the fossa for the gallbladder and the fissure for the ligamentum teres; 2. SYN: quadrangular lobule. 3. SYN: precuneus.
renal l. SYN: kidney lobes.
Riedel l. an occasional tonguelike process extending downward from the right l. of the liver lateral to the gallbladder; a similar process may, though rarely, extend from the left l.. SYN: lobus appendicularis, lobus linguiformis.
right l. [TA] the right subdivision of several glands, e.g., prostate, thyroid, thymus. SYN: lobus dexter [TA] .
right l. of liver [TA] the largest l. of the liver, separated from the left l. anteriorly and superiorly by the falciform and coronary ligaments and from the caudate and quadrate lobes by the sulcus for the vena cava and the fossa for the gallbladder. SYN: lobus hepatis dexter [TA] .
Spigelius l. SYN: posterior hepatic segment I.
superior l. of (right/left) lung the l. of the right lung that lies above the oblique and horizontal fissures and includes the apical (S I), posterior (S II), and anterior (S III) bronchopulmonary segments; in the left lung, the l. lies above the oblique fissure and contains the apicoposterior (S I + II), anterior (S III), superior lingular (S IV), and inferior lingular (S V) segments. SYN: lobus superior pulmonis (dextri et sinistri) [TA] , upper l. of lung&star.
supplemental l. in dental anatomy, an extra l.; one that is not included in the typical formation of a tooth.
temporal l. [TA] a long l., the lowest of the major subdivisions of the cortical mantle, forming the posterior two-thirds of the ventral surface of the cerebral hemisphere, separated from the frontal and parietal lobes above it by the lateral sulcus arbitrarily delineated by an imaginary plane from the occipital l. with which it is continuous posteriorly. The temporal l. has a heterogeneous composition: in addition to a large neocortical component consisting of the superior, middle, and inferior temporal gyri and the lateral and medial occipitotemporal gyri, it includes the largely juxtallocortical parahippocampal gyrus with its paleocortical (olfactory) uncus and, beneath the latter, the amygdala. SYN: lobus temporalis [TA] , temporal cortex.
lobes of thyroid gland [TA] the two major divisions of the gland lying on the right and left side of the trachea and connected by the isthmus. A smaller pyramidal l. is frequently present as an upward extension from the isthmus. SYN: lobi glandulae thyroideae [TA] .
upper l. of lung superior l. of (right/left) lung.

lobectomy
lobectomy (lo-bek′to-me)

Excision of a lobe of any organ or gland. [G. lobos, lobe, + ektome, excision]

lobelia
lobelia (lo-be′le-a)

1. The dried leaves and tops of L. inflata (family Lobeliaceae); it contains several alkaloids: lobeline, lobelamine, lobelanidine, lobelanine, norlobelanine, norlobelanidine, and isolobelanine. The fluid extract and the tincture have been used as an expectorant in asthma and chronic bronchitis. 2. One of a class of alkaloids isolated from l. (1). 3. Any plant of the genus L.. SYN: asthma-weed (1) , wild tobacco.

lobeline
lobeline, lobelin (lo′be-len, lob′e-len, -lin)

A piperidylacetophenone; an alkaloid of lobelia with the same actions as nicotine, but with less potency.
l. sulfate a form of l. occurring in yellow friable masses, soluble in water; used in whooping cough and asthma; it has been suggested as a smoking deterrent.

lobi
lobi (lo′bi)

Plural of lobus. [L.]

lobitis
lobitis (lo-bi′tis)

Inflammation of a lobe.

Lobo
Lobo

Jorge, Brazilian physician, 1900–1979. See L. disease.

Loboa loboi
Loboa loboi (lo-bo′a lo-bo′e)

A species of fungus causing lobomycosis. The organism has not been grown in culture.

lobomycosis
lobomycosis (lo-bo-mi-ko′sis)

A chronic localized mycosis of the skin reported from South America resulting in granulomatous nodules or keloids that contain budding, thick-walled cells about 9 μm in diameter, i.e., the tissue form of Loboa loboi, the causative fungus, which has not been cultured. Also occurs in dolphins. SYN: Lobo disease.

lobopodium
lobopodium, pl .lobopodia (lo′bo-po′de-um, -de-a)

A thick lobose pseudopodium. [G. lobos, lobe, + pous, foot]

lobose
lobose, lobous (lo′bos, lo′bus)

SYN: lobate.

lobotomy
lobotomy (lo-bot′o-me)

1. Incision into a lobe. 2. Division of one or more nerve tracts in a lobe of the cerebrum. [G. lobos, lobe, + tome, a cutting]
prefrontal l. division of one or more nerve tracts in the prefrontal area of the brain for surgical treatment of pain and emotional disorder. SYN: prefrontal leukotomy.
transorbital l. l. by an approach through the roof of the orbit, behind the frontal sinus. SYN: transorbital leukotomy.

Lobry de Bruyn
Lobry de Bruyn

Cornelius A., Dutch chemist, 1857–1904. See L.-van Ekenstein transformation.

Lobstein
Lobstein

Johann F.D., German pathologist, 1777–1840. See L. ganglion.

lobular
lobular (lob′u-lar)

Relating to a lobule.

lobulate
lobulate, lobulated (lob′u-lat, -ed)

Divided into lobules.

lobule
lobule (lob′ul) [TA]

A small lobe or subdivision of a lobe. SYN: lobulus [TA] .
ala central l. [TA] SYN: wing of central l.. SYN: pars inferior alae lobuli centralis [TA] , pars superior ali lobuli centralis [TA] .
ansiform l. comprises the greater part of the hemisphere of the cerebellum; its superior and inferior surfaces are separated by the horizontal fissure into major parts known as crus I (superior semilunar l.) and crus II (inferior semilunar l.).
anterior lunate l. SYN: superior semilunar l..
l. of auricle [TA] the lowest part of the auricle; it consists of fat and fibrous tissue not reinforced by the auricular cartilage; it is often utilized as a site to obtain a small sample of blood using a lancet. SYN: lobulus auriculae [TA] , ear lobe.
biventer l. [TA] a l. on the undersurface of each cerebellar hemisphere, divided by a curved sulcus into a lateral and medial portion; it corresponds to the pyramid of the vermis. SYN: lobulus biventer [TA] , biventral l., cuneiform lobe, lobulus biventralis, lobulus cuneiformis.
biventral l. SYN: biventer l..
central l. [TA] SYN: central l. of cerebellum.
central l. of cerebellum a division of the superior vermis of the cerebellum between the lingula and the culmen consisting of lobules II and III. SYN: central l. [TA] , lobulus centralis corporis cerebelli [TA] .
conical lobules of epididymis lobules of epididymis.
cortical lobules of kidney one of the subdivisions of the kidney, consisting of a medullary ray and that portion of the convoluted part (renal corpuscles and convoluted tubules) associated with its collecting duct. SYN: lobulus corticalis renalis, renal cortical l., renculus (1) , reniculus (1) , renunculus (1) .
crescentic lobules of the cerebellum archaic term for lobulus semilunaris inferior and lobulus semilunaris superior.
lobules of epididymis [TA] the coiled portion of the efferent ductules that constitute the head of the epididymis; these join the ductus epididymidis. SYN: lobuli epididymidis [TA] , coni epididymidis&star, conical lobules of epididymis&star, coni vasculosi, Haller cones, vascular cones.
gracile l. [TA] the anterior portion of the posteroinferior l. of the cerebellum, the posterior portion being the semilunar l. inferior; the two are continuous with the tuber of the vermis. SYN: lobulus paramedianus [TA] , lobulus gracilis&star, paramedian l.&star, slender l..
hepatic l. SYN: lobules of liver.
inferior parietal l. [TA] the area of the parietal lobe of the cerebrum lying below the interparietal sulcus; it contains the angular and the supramarginal gyri. SYN: lobulus parietalis inferior [TA] , inferior parietal gyrus.
inferior semilunar l. [TA] the part of the superior surface of the cerebellar hemisphere lying behind the horizontal fissure. SYN: lobulus semilunaris inferior [TA] , crus II, posterior lunate l..
lobules of liver [TA] the conceptual polygonal histologic unit of the liver consisting of masses of liver cells arranged around a central vein, a terminal branch of one of the hepatic veins; at the periphery are located preterminal and terminal branches of the portal vein, hepatic artery, and bile duct; hepatic lobules have anatomic reality in pig liver or pathologically in humans, when fibrous septa are present. SYN: lobulus hepatis [TA] , hepatic l..
lobules of mammary gland [TA] subdivisions of the lobes of the mammary gland. SYN: lobuli glandulae mammariae [TA] .
paracentral l. [TA] a division of the medial aspect of the cerebral cortex, lying above the cingulate sulcus and bounded by the paracentral sulcus in front and the marginal part of the cingulate sulcus behind; this l. is formed by the anterior paracentral gyrus and the posterior paracentral gyrus. SYN: lobulus paracentralis [TA] .
paramedian l. gracile l..
portal l. of liver a conceptual unit of the liver, emphasizing its exocrine function in bile secretion, which comprises a roughly triangular shaped cross-sectional area with a portal canal at its center and three or more venae centrales hepatis at its periphery.
posterior lunate l. SYN: inferior semilunar l..
primary pulmonary l. SYN: pulmonary acinus.
quadrangular l. the main portion of the superior part of each hemisphere of the cerebellum, corresponding in current terminology to the anterior quadrangular l.; the hemisphere portions of the culmen (lobules IV and V) of the vermis consist of an anterior part (l. HIV) and a posterior part (l. HV); located between the preculminate and primary fissures. SYN: lobulus quadrangularis, lobulus quadratus (1) , lobus quadratus, quadrate lobe (2) , quadrate l. (1) .
quadrate l. 1. SYN: quadrangular l.. 2. SYN: precuneus.
renal cortical l. SYN: cortical lobules of kidney.
respiratory l. SYN: pulmonary acinus.
secondary pulmonary l. a pyramidal mass of lung tissue whose sides are bounded by the incomplete interlobular connective tissue septa and whose base, which is 1 to 2 cm in diameter, usually faces the pleural surface of the lung; lobules that occupy a more central position in the lung are not well defined and are considered to consist of three to five pulmonary acini with proximate terminal bronchioles.
simple l. [TA] the smaller anterior part of the posterior lobe of the cerebellum, demarcated by the primary fissure from the anterior lobe rostrally and by the posterior superior fissure from the large ansiform l. caudally. SYN: lobulus simplex [TA] .
slender l. SYN: gracile l..
superior parietal l. [TA] the area of the convex surface of the parietal lobe of the cerebrum lying between the longitudinal fissure and the interparietal sulcus caudal to the postcentral gyrus; it is continuous with the precuneus on the medial aspect of the hemisphere. SYN: lobulus parietalis superior [TA] , superior parietal gyrus.
superior semilunar l. [TA] the part of the superior surface of the cerebellar hemisphere lying between the horizontal and ansoparamedian fissures and adjoining the folium and parts of the tuber of the vermis. SYN: lobulus semilunaris superior [TA] , anterior lunate l., crus I.
lobules of testis [TA] the subdivisions of the parenchyma of the testis formed by delicate fibrous septa that pass inward from the tunica albuginea to converge at the mediastinum testis. SYN: lobuli testis [TA] .
lobules of thymus [TA] areas of thymic tissue 0.5 to 2 mm in diameter with a cortex and medulla. SYN: lobuli thymi [TA] .
lobules of thyroid gland [TA] the subdivisions of the lobe of the thyroid gland, consisting of incompletely separated, irregular groups of thyroid follicles (20–40 in number) bound together by delicate connective tissue. SYN: lobuli glandulae thyroideae [TA] .

lobulet
lobulet, lobulette (lob′u-let′)

A very small lobule or one of the smaller subdivisions of a lobule.

lobulus
lobulus, gen. and pl. lobuli (lob′u-lus, u-li) [TA]

SYN: lobule. [Mod. L. dim. of lobus, lobe]
l. auriculae [TA] SYN: lobule of auricle.
l. biventer [TA] SYN: biventer lobule.
l. biventralis SYN: biventer lobule.
l. centralis corporis cerebelli [TA] SYN: central lobule of cerebellum.
l. clivi SYN: declive.
l. corticalis renalis SYN: cortical lobules of kidney, under lobule.
l. culminis SYN: culmen.
l. cuneiformis SYN: biventer lobule.
lobuli epididymidis [TA] SYN: lobules of epididymis, under lobule.
l. folii the part of the superior vermis of the cerebellum lying immediately behind the posterior superior fissure and caudal to the l. clivi.
l. fusiformis SYN: fusiform gyrus.
lobuli glandulae mammariae [TA] SYN: lobules of mammary gland, under lobule.
lobuli glandulae thyroideae [TA] SYN: lobules of thyroid gland, under lobule.
l. gracilis gracile lobule.
l. hepatis [TA] SYN: lobules of liver, under lobule.
l. paracentralis [TA] SYN: paracentral lobule.
l. paramedianus [TA] SYN: gracile lobule.
l. parietalis inferior [TA] SYN: inferior parietal lobule.
l. parietalis superior [TA] SYN: superior parietal lobule.
l. quadrangularis SYN: quadrangular lobule.
l. quadratus 1. SYN: quadrangular lobule. 2. SYN: precuneus.
l. semilunaris inferior [TA] SYN: inferior semilunar lobule.
l. semilunaris superior [TA] SYN: superior semilunar lobule.
l. simplex [TA] SYN: simple lobule.
lobuli testis [TA] SYN: lobules of testis, under lobule.
lobuli thymi [TA] SYN: lobules of thymus, under lobule.

lobus
lobus, gen. and pl. lobi (lo′bus, lo′bi) [TA]

SYN: lobe. [LL. fr. G. lobos]
l. anterior hypophyseos [TA] SYN: adenohypophysis.
l. appendicularis SYN: Riedel lobe.
l. azygos pulmonis dextri SYN: azygos lobe of right lung.
l. caudatus posterior hepatic segment I.
lobi cerebri [TA] the major divisions of the cerebral hemisphere; they include the frontal, parietal, temporal, and occipital lobes, named for the overlying bones of the skull, and the limbic lobe. The insula may also be regarded as a lobe (l. insularis [TA]) because it is separated from the frontal, parietal, and temporal opercula by the circular sulcus of the insula [TA]. SYN: cerebral lobes.
l. clivi obsolete term for the clivus monticuli and the posterior crescentic lobules of the cerebellum, considered as one lobe.
l. dexter [TA] SYN: right lobe.
l. falciformis SYN: cingulate gyrus.
l. flocculonodularis [TA] SYN: flocculonodular lobe.
l. frontalis [TA] SYN: frontal lobe of cerebrum.
lobi glandulae mammariae [TA] SYN: lobes of mammary gland, under lobe.
lobi glandulae thyroideae [TA] SYN: lobes of thyroid gland, under lobe.
l. glandularis hypophyseos SYN: adenohypophysis.
l. hepatis dexter [TA] SYN: right lobe of liver.
l. hepatis sinister [TA] SYN: left lobe of liver.
l. inferior pulmonis dextri et sinistri [TA] SYN: inferior lobe of (left / right) lung.
l. insula [TA] the area of cerebral cortex located internal to the lateral sulcus and separated from the adjacent frontal, parietal and temporal opercula by the circular sulcus of the insula; composed of short and long gyri separated by the central sulcus of the insula. SEE ALSO: insula. SYN: insular lobe&star, l. insularis&star, insular part, pars insularis.
l. insularis l. insula.
l. limbicus [TA] SYN: limbic lobe.
l. linguiformis SYN: Riedel lobe.
l. medius prostatae [TA] SYN: middle lobe of prostate.
l. medius pulmonis dextri [TA] SYN: middle lobe of right lung.
l. nervosus [TA] SYN: neurohypophysis.
l. occipitalis [TA] SYN: occipital lobe of cerebrum.
l. parietalis [TA] SYN: parietal lobe of cerebrum.
l. posterior hypophyseos neurohypophysis. SEE ALSO: pituitary gland.
l. prostatae [TA] SYN: lobe of prostate.
l. pyramidalis glandulae thyroideae [TA] SYN: pyramidal lobe of thyroid gland.
l. quadratus SYN: quadrangular lobule.
l. renalis [TA] SYN: kidney lobes, under lobe.
l. sinister [TA] SYN: left lobe.
l. superior pulmonis (dextri et sinistri) [TA] SYN: superior lobe of (right/left) lung.
l. temporalis [TA] SYN: temporal lobe.

LOCA
LOCA

Abbreviation for low osmolar contrast agent.

local
local (lo′kal)

Having reference or confined to a limited part; not general or systemic. [L. localis, fr. locus, place]

localization
localization (lo′kal-i-za′shun)

1. Limitation to a definite area. 2. The reference of a sensation to its point of origin. 3. The determination of the location of a morbid process.
auditory l. in sensory psychology, the naming or pointing to directions from which sounds emanate.
cerebral l. 1. the mapping of the cerebral cortex into areas and the correlation of the various areas with cerebral function. 2. determination of the site of a brain lesion on the basis of the signs and symptoms manifested by the patient or by neuroimaging.
germinal l. SYN: fate map.
radiotherapy l. planning the size and alignment of radiation beams to encompass the neoplasm to be treated.
spatial l. the reference of a visual sensation to a definite locality in space.
stereotaxic l. l. of intracerebral nuclei by coordinates with reference to anatomic landmarks in the brain.

localized
localized (lo′kal-izd)

Restricted or limited to a definite part.

locant
locant (lo′kant)

A number or letter preceding a substituent name in the name of a complex chemical that specifies the position (location) of the substituent on the parent molecule; e.g., 5 in 5-methyluridine, S in S-adenosylmethionine.

locator
locator (lo′ka-ter, tor)

An instrument or apparatus for finding the position of a foreign object in tissue.

lochia
lochia (lo′ke-a)

Discharges from the vagina of mucus, blood, and tissue debris, following childbirth. [G. neut. pl. of lochios, relating to childbirth, fr. lochos, childbirth]
l. alba the last discharge no longer tinged with blood.
l. rubra the initial discharge stained with blood.
l. sanguinolenta thick, dark red vaginal discharge seen a few days after delivery.
l. serosa a thin and watery l..

lochial
lochial (lo′ke-al)

Relating to the lochia.

lochiometra
lochiometra (lo-ke-o-me′tra)

Distention of the uterus with retained lochia. [G. metra, womb]

lochiorrhagia
lochiorrhagia (lo-ke-o-ra′je-a)

SYN: lochiorrhea. [lochia + G. rhegnymi, to burst forth]

lochiorrhea
lochiorrhea (lo-ke-o-re′a)

Profuse flow of the lochia. SYN: lochiorrhagia. [lochia + G. rhoia, a flow]

loci
loci (lo′si)

Plural of locus.

lock
lock (lok)

A device for holding or closing.
English l. articulation of the blades of obstetrical forceps consisting of a socket on the shank at the junction with the handle in a similar socket on the other shank; used in Simpson forceps.
sliding l. a slot on one shank of obstetrical forceps (as in Kjelland forceps) that allows the shanks to move forward and backward independently.

Locke
Locke

Frank S., British physiologist, 1871–1949. See Cabot-L. murmur, L. solutions, under solution, L.-Ringer solution.

lockjaw
lockjaw (lok′jaw)

SYN: trismus.

Lockwood
Lockwood

Charles B., English anatomist and surgeon, 1858–1914. See L. ligament.

LOCM
LOCM

Abbreviation for low osmolar contrast medium.

locomotive
locomotive (lo-ko-mo′tiv)

SYN: locomotor.

locomotor
locomotor (lo-ko-mo′ter)

Relating to locomotion, or movement from one place to another. SYN: locomotive, locomotory. [L. locus, place, + L. moveo, pp. motus, to move]

locomotorial
locomotorial (lo-ko-mo-to′re-al)

Relating to the locomotorium.

locomotorium
locomotorium (lo′ko-mo-to′re-um)

The locomotor apparatus of the body. [L. locus, place, + motorius, moving]

locomotory
locomotory (lo-ko-mo′to-re)

SYN: locomotor.

locular
locular (lok′u-lar)

Relating to a loculus.

loculate
loculate (lok′u-lat)

Containing numerous loculi.

loculation
loculation (lok-u-la′shun)

1. A loculate region in an organ or tissue, or a loculate structure formed between surfaces of organs, mucous or serous membranes, and so on. 2. The process that results in the formation of a loculus or loculi.

loculus
loculus, pl .loculi (lok′u-lus, -li)

A small cavity or chamber. [L. dim. of locus, place]

locum tenant
locum tenant (lo′kum ten′ent)

A temporary substitution of one physician by another. SYN: locum tenens. [partial anglicization of locum tenens]

locum tenens
locum tenens (lo′kum ten′ens)

SYN: locum tenant. [L. one holding a place]

locus
locus, pl .loci (lo′kus, lo′si)

1. A place; usually, a specific site. 2. The position that a gene occupies on a chromosome. 3. The position of a point, as defined by the coordinates on a graph. [L.]
l. caeruleus [TA] a shallow depression, of a blue color in the fresh brain, lying laterally in the most rostral portion of the rhomboidal fossa near the cerebral aqueduct; it lies near the lateral wall of the fourth ventricle and consists of about 20,000 melanin-pigmented neuronal cell bodies whose norepinephrine-containing axons have a remarkably wide distribution in the cerebellum as well as in the hypothalamus and cerebral cortex. SYN: l. cinereus, l. ferrugineus, substantia ferruginea.
l. cinereus SYN: l. caeruleus.
cis-acting l. a section of DNA that affects the activity of DNA sequences on that same molecule of DNA.
complex l. a set of closely linked genetic loci with a common function, as in the major histocompatibility complex l..
l. of control a theoretical construct designed to assess a person's perceived control over his/her own behavior; classified as internal if the person feels in control of events, external if others are perceived to have that control.
l. ferrugineus SYN: l. caeruleus.
genetic l. the set of homologous parts of a pair of chromosomes that may be occupied by allelic genes. The l. thus comprises a pair of locations (except in the X chromosome in males). The concept of a l. is somewhat idealized, not taking into account accidents that may occur in meiosis such as duplication of loci as a result of unequal crossing-over, translocations, inversions, etc.
marker l. a l. on a chromosome or in a stretch of DNA that can be identified ( e.g., a restriction fragment length polymorphism) and can serve in linkage analysis and in the isolation of a disease gene. SEE ALSO: linkage marker.
l. niger SYN: substantia nigra.
l. perforatus anticus SYN: anterior perforated substance.
l. perforatus posticus SYN: posterior perforated substance.
sex-linked l. any l. that in normal karyotypes is borne on a heterosome; commonly but incorrectly applied to an X-linked l..
X-linked l. any l. that in normal karyotypes is borne on the X chromosome.
Y-linked l. any (haploid) l. that in normal karyotypes is borne on the Y chromosome. The known content is so far small.

lod score
lod score (lod skor)

A number used in genetic linkage studies; logarithm (decadic) of the odds in favor of genetic linkage. [logarithm + odds]

Loeb
Loeb

Leo, U.S. pathologist, 1869–1959. See L. deciduoma.

Loeffler
Loeffler

Friedrich A.J., German bacteriologist and surgeon, 1852–1915. See L. bacillus, L. blood culture medium, L. stain, L. caustic stain, L. methylene blue, Klebs-L. bacillus, L. syndrome I, L. syndrome II.

Loevit
Loevit

Moritz, Austrian pathologist, 1851–1918. See L. cell.

Loewenthal
Loewenthal

Wilhelm, German physician, 1850–1894. See L. bundle, L. reaction, L. tract.

lofentanil
lofentanil (lo-fen′ta-nil)

A potent, long-lasting narcotic and analgesic that is chemically related to fentanyl.

Löffler
Löffler

Wilhelm, Swiss physician, 1887–1972. See L. disease, L. endocarditis, L. parietal fibroplastic endocarditis, L. syndrome.

log- log-

See logo-.

Logan
Logan

William H.G., early 20th century U.S. plastic surgeon. See L. bow.

logarithm
logarithm (log′ar-ridhm)

If a number, x, is expressed as a power of another number, y, i.e., if x = yⁿ, then n is said to be the l. of x to base y. Common logarithms are to the base 10; natural or Napierian logarithms are to the base e, a mathematical constant. [G. logos, word, ratio, + arithmos, number]

logetronography
logetronography (log-e-tron-og′ra-fe)

A method of photographic printing in which fine details are emphasized by electronic enhancement of their contrast; formerly used for reproducing radiographic images.

-logia -logia

1. The study of the subject noted in the body of the word, or a treatise on the same; the Eng. equivalent is -logy, or, with a connecting vowel, -ology. [G. logos, discourse, treatise] 2. Collecting or picking. [G. lego, to collect]

logit
logit (log′it)

The logarithm of the ratio of frequencies of two different categorical and mutually exclusive outcomes such as healthy and sick.

logo- logo-, log-

Speech, words. [G. logos, word, discourse]

logopedia
logopedia (log-o-pe′de-a)

SYN: logopedics.

logopedics
logopedics (log′o-pe′diks)

A branch of science concerned with the physiology and pathology of the organs of speech and with the correction of speech defects. SYN: logopedia. [logo- + G. pais (paid-), child]

logorrhea
logorrhea (log-o-re′a)

Rarely used term for abnormal or pathologic talkativeness or garrulousness. [logo- + G. rhoia, a flow]

logospasm
logospasm (log′o-spazm)

1. SYN: stuttering. 2. SYN: explosive speech. [logo- + G. spasmos, spasm]

logotherapy
logotherapy (log′o-thar′a-pe)

A form of psychotherapy which places special emphasis on the patient's spiritual life and on the physician as “medical minister.” [logo- + G. therapeia, cure]

-logy -logy

See -logia. [G. logos, treatise, discourse]

Lohlein-Baehr lesion
Lohlein-Baehr lesion

See under lesion.

loiasis
loiasis (lo-i′a-sis)

A chronic disease caused by the filarial nematode Loa loa, with symptoms and signs first occurring approximately 3–4 years after a bite by an infected tabanid fly. When the infective larvae mature, the adult worms move about in an irregular course through the connective tissue of the body (as rapidly as 1 cm per minute), frequently becoming visible beneath the skin and mucous membranes; e.g., in the back, scalp, chest, inner surface of the lip, and especially on the conjunctiva. The worms provoke hyperemia and exudation of fluid, often a host response to the worm products, a Calabar or fugitive swelling which causes no serious damage and subsides as the parasites move on; the patient is annoyed by the “creeping” in the tissues and intense itching, as well as occasional pain, especially when the swelling is in the region of tendons and joints. Most patients have an eosinophilia of 10–30 or 40% in the circulating blood. SYN: Calabar swelling, fugitive swelling.

loin
loin (loyn)

The part of the side and back between the ribs and the pelvis. SYN: lumbus. [Fr. longe; E. lumbus]

Lok
Lok

See Luer-L. syringe.

loliism
loliism (lo′li-izm)

Poisoning by the seeds of a grass, Lolium temulentum (in the form of flour made into bread), characterized by giddiness, tremor, green vision, dilated pupils, prostration, and sometimes vomiting. [L. lolium, darnel, tares]

Lombard
Lombard

Etienne, French physician, 1868–1920. See L. voice-reflex test.

lomustine
lomustine (lo-mus′ten)

An antineoplastic agent. SYN: CCNU.

Long
Long

John H., U.S. physician, 1856–1927. See L. coefficient, L. formula.

long-chain acyl-CoA dehydrogenase
long-chain acyl-CoA dehydrogenase

See acyl-CoA dehydrogenase (NADPH).

long-chain fatty acid-CoA ligase
long-chain fatty acid-CoA ligase

Fatty acid thiokinase (long-chain), a ligase forming acyl-CoA, AMP, and pyrophosphate from long-chain fatty acids, ATP, and coenzyme A. SYN: acyl-activating enzyme (1) , dodecanoyl-CoA synthetase.

longevity
longevity (lon-jev′i-te)

Duration of a particular life beyond the norm for the species. SEE ALSO: lifespan. SYN: macrobiosis.

longitudinal
longitudinal (lon′ji-too′di-nal) [TA]

1. Running lengthwise; in the direction of the long axis of the body or any of its parts. SYN: longitudinalis [TA] . 2. Studied over a period of time, diachronic; contrast with cross-sectional or synchronic, which give equivalent results only under certain strict conditions of stability and equilibrium. Strict attention to these conditions is of the greatest importance in the study of survivorship either in demographics or in cell economy (such as the survival pattern of the erythrocytes and platelets). [L. longitudo, length]

longitudinalis
longitudinalis (lon′ji-too′di-na′lis) [TA]

SYN: longitudinal (1) .

longitype
longitype (lon′ji-tip)

SYN: ectomorph.

Longmire
Longmire

William P., Jr., U.S. surgeon, 1913–1977. See L. operation.

Looney
Looney

Joseph M., U.S. biochemist, *1896. See Folin-L. test.

loop
loop (loop)

1. A sharp curve or complete bend in a vessel, cord, or other cylindrical body, forming an oval or circular ring. SEE ALSO: ansa. 2. A wire (usually of platinum or nichrome) fixed into a handle at one end and bent into a circle at the other, rendered sterile by flaming, and used to transfer microorganisms. [M.E. loupe]
Biebl l. a continuous l. of small intestine brought through the abdominal wall to a subcutaneous location, for observation of motility.
bulboventricular l. the portion of the early-somite embryonic cardiac tube that evolves into the ventricle and bulbus cordis. SYN: ventricular l..
capillary l. small blood vessel in the dermal papillae.
cervical l. SYN: ansa cervicalis.
cruciform loops a secondary structure of DNA formed by the hydrogen bonding of self-complementary regions.
D l. a structure in replicating circular DNA. SYN: displacement l..
displacement l. SYN: D l..
gamma l. the reflex arc consisting of small anterior horn cells and neuroma, their small fibers projecting to the intrafusal bundle producing its contraction, which initiates the afferent impulses that pass through the posterior root to the anterior horn cells, inducing a stretch reflex. SYN: gamma motor neurons, gamma motor system, Granit l..
Gerdy interatrial l. a muscular fasciculus in the interatrial septum of the heart, passing backward from the atrioventricular groove.
Granit l. SYN: gamma l..
hairpin loops single-stranded DNA and RNA can fold back on itself under the proper conditions forming irregular double-helical loops.
Henle l. SYN: nephronic l..
l. of hypoglossal nerve SYN: ansa cervicalis.
Hyrtl l. a communicating l. between the right and left hypoglossal nerves, lying between the geniohyoid and genioglossus muscles or in the substance of the geniohyoid; it is found in about one in ten persons. SYN: Hyrtl anastomosis.
lenticular l. the pallidal efferent fibers curving around the medial border of the internal capsule. SYN: ansa lenticularis [TA] , lenticular ansa.
memory l. an electronic device for retrieving data that had been stored and/or displayed upon the oscilloscope at an earlier time; used for reviewing electrical events immediately preceding a specific disturbance.
Meyer-Archambault l. the fibers of the visual radiation that l. around the tip of the temporal horn.
nephronic l. the U-shaped part of the nephron extending from the proximal to the distal convoluted tubules, consisting of descending and ascending limbs, located in the medulla renalis and medullary ray. SYN: Henle ansa, Henle l..
peduncular l. SYN: ansa peduncularis.
loops of spinal nerves loops of the spinal nerves, connecting ventral primary rami of the spinal nerves. SYN: ansae nervorum spinalium.
subclavian l. SYN: ansa subclavia.
vector l. a smooth or irregular, usually elliptical, curve representing the average direction and magnitude of the heart's action from moment to moment throughout the cardiac cycle. SEE ALSO: vector (2) , vectorcardiogram.
ventricular l. SYN: bulboventricular l..
Vieussens l. SYN: ansa subclavia.

loosening of association
loosening of association

A manifestation of a severe thought disorder characterized by the lack of an obvious connection between one thought or phrase and the next, or with the response to a question.

Looser
Looser

Emil, Swiss physician, 1877–1936. See L. zones, under zone.

LOP
LOP

Abbreviation for left occipitoposterior position.

lop-ear
lop-ear (lop′er)

Congenital abnormality of the external ear, with poor development of helix and anthelix. SYN: bat ear.

loperamide hydrochloride
loperamide hydrochloride (lo-per′a-mid)

An antiperistaltic agent used to treat diarrhea.

lophodont
lophodont (lof′o-dont)

Having the crowns of the molar teeth formed in transverse or longitudinal crests or ridges, in contrast to bunodont. [G. lophos, ridge, + odous, tooth]

Lophophora williamsii
Lophophora williamsii (lo-fof′o-ra wil-yam′se-i)

The botanical origin of peyote (mescal button); it contains over a dozen alkaloids, of which mescaline is the most important; others are pellotine, anhalomine, anhalonidine, anhalamine, anhalinine, anhalidine, and lophophorine.

lophotrichate
lophotrichate (lo-fot′ri-kat)

SYN: lophotrichous.

lophotrichous
lophotrichous (lo-fot′ri-kus)

Referring to a bacterial cell with two or more flagella at one or both poles. SYN: lophotrichate. [G. lophos, crest, + thrix, hair]

lopremone
lopremone (lo′pre-mon)

Former name for protirelin.

Lorain
Lorain

Paul, French physician, 1827–1875. See L. disease, L.-Lévi dwarfism, L.-Lévi infantilism, L.-Lévi syndrome.

lorazepam
lorazepam (lo-ra′ze-pam)

An antianxiety drug of the benzodiazepine group.

lorcainide
lorcainide (lor-ka-nid)

An antiarrhythmic agent used for the treatment of ventricular arrhythmias; much like a cardiac depressant (antiarrhythmic).

lordoscoliosis
lordoscoliosis (lor′do-sko-le-o′sis)

Combined backward and lateral curvature of the spine. [G. lordos, bent back, + skoliosis, crookedness, fr. skolios, bent, aslant]

lordosis
lordosis (lor-do′sis) [TA]

An anteriorly convex curvature of the vertebral column; the normal lordoses of the cervical and lumbar regions are secondary curvatures of the vertebral column, acquired postnatally. SYN: hollow back, saddle back. [G. l., a bending backward]
cervical l. [TA] the normal, anteriorly convex curvature of the cervical segment of the vertebral column; cervical l. is a secondary curvature of the vertebral column, acquired postnatally as the infant lifts its head. SYN: l. cervicis [TA] , l. colli&star.
l. cervicis [TA] SYN: cervical l..
l. colli cervical l..
l. lumbalis [TA] SYN: lumbar l..
lumbar l. [TA] the normal, anteriorly convex curvature of the lumbar segment of the vertebral column; lumbar l. is a secondary curvature of the vertebral column, acquired postnatally as the upright posture is assumed when one learns to walk. SYN: l. lumbalis [TA] , lumbar flexure.

lordotic
lordotic (lor-dot′ik)

Pertaining to or marked by lordosis.

Lorenz
Lorenz

Adolf, Austrian surgeon, 1854–1946. See L. sign.

Loschmidt
Loschmidt

Joseph (Johann), Czech chemist and physicist, 1821–1895. See L. number.

LOT
LOT

Abbreviation for left occipitotransverse position.

lotion
lotion (lo′shun)

A class of pharmacopeial preparations that are liquid suspensions or dispersions intended for external application; some consist of finely powdered, insoluble solids held in more or less permanent suspension by suspending agents or surface-active agents, or both; others are oil-in-water emulsions stabilized by surface-active agents. [L. lotio, a washing, fr. lavo, to wash]

Louis
Louis

Pierre C.A., French physician, 1787–1872. See L. angle, L. law.

Louis-Bar
Louis-Bar

Denise, mid-20th century French physician. See Louis-Bar syndrome.

loupe
loupe (loop)

A magnifying lens. [Fr.]
binocular l. a magnifying device, attached to spectacles or a headband, worn as a visual aid when performing operations on small structures.

louse
louse, pl .lice (lows, lis)

Common name for members of the ectoparasitic insect orders Anoplura (sucking lice) and Mallophaga (biting lice). Important species are Felicola subrostrata (cat l.), Goniocotes gallinae (fluff l.), Goniodes dissimilis (brown chicken l.), Haemodipsus ventricosus (rabbit l.), Lipeurus caponis (wing l.), Menacanthus stramineus (chicken body l.), Pthirus pubis (crab or pubic l.), and Polyplax serratus (mouse l.). [A.S. lus]
biting l., chewing l., feather l. ectoparasites (order Mallophaga) chiefly found on birds, where they feed on feathers, hair, epidermal debris, and (less commonly) on blood; they possess nipper-like, heavily sclerotized mandibles and a characteristic broad head; many species are host-specific.
sea l. the very small larvae of the thimble jellyfish (Linuche unguiculata).
sucking l. blood-sucking mammalian ectoparasites (order Anoplura), characterized by a narrow head with piercing and sucking mouthparts that lie in a sac concealed in the head.

lousy
lousy (low′se)

SYN: pediculous.

lovastatin
lovastatin (lo-va-stat′in)

A cholesterol-lowering agent, isolated from a strain of Aspergillus terreus, that reduces both normal and elevated serum cholesterol. SYN: mevinolin.

Lovén
Lovén

Otto C., Swedish physician, 1835–1904. See L. reflex.

Lovibond
Lovibond

J.L., 20th century English dermatologist. See L. angle, L. profile sign.

Lowe
Lowe

Charles U., U.S. pediatrician, *1921. See L. syndrome, L.-Terrey-MacLachlan syndrome.

Löwenberg
Löwenberg

Benjamin B., French laryngologist, 1836–1905. See L. canal, L. forceps, L. scala.

Lower
Lower

SYN: inferior. See L. ring, L. tubercle.

Lown
Lown

Bernard, U.S. cardiologist, *1921. See L.-Ganong-Levine syndrome.

Lowry
Lowry

Oliver H., U.S. biochemist, *1910. See L.-Folin assay, L. protein assay.

Lowry
Lowry

R. Brian, 20th century Irish medical geneticist in Canada. See Coffin-L. syndrome.

Lowsley
Lowsley

Oswald S., U.S. urologist, 1884–1955. See L. tractor.

loxapine
loxapine (lok′sa-pen)

2-Chloro-11-(4-methyl-1-piperazinyl)dibenz[b,f][1,4]-oxazepine; a neuroleptic antipsychotic agent used as the succinate and hydrochloride salts.

Loxosceles
Loxosceles (lok-sos′e-lez)

A genus of venomous spiders, the brown spiders, marked by a fiddle-shaped pattern on the cephalothorax, and found chiefly in South America. They inflict a highly ulcerative, spreading dermal lesion at the site of the bite (loxoscelism). Important species include L. laeta, the Chilean brown recluse spider; L. reclusus, the brown recluse spider of North America; and L. rufipes, the Peruvian brown spider. [G. loxos, oblique, + skelos, leg]

loxoscelism
loxoscelism (lok-sos′e-lizm)

A clinical illness produced by the brown recluse spider, Loxosceles reclusus, of North America; characterized by gangrenous slough at the site of the bite, nausea, malaise, fever, hemolysis, and thrombocytopenia.

Loxotrema ovatum
Loxotrema ovatum (lok-so-tre′ma o-va′tum)

Former name for Metagonimus yokogawai. [G. loxos, slanting, + trema, a hole; L. ovatus, egg-shaped]

lozenge
lozenge (loz′enj)

SYN: troche. [Fr. losange, fr. lozangé, rhombic]

LPH
LPH

Abbreviation for lipotropic hormone.

L.P.N.
L.P.N.

Abbreviation for licensed practical nurse.

LPO
LPO

Abbreviation for left posterior oblique, a radiographic projection.

LPS
LPS

Abbreviation for lipopolysaccharide.

Lr
Lr, L_r

See L. dose.

Lr
Lr

Symbol for lawrencium.

L.R.C.P.
L.R.C.P.

Abbreviation for Licentiate of the Royal College of Physicians (of England).

L.R.C.P.(E)
L.R.C.P.(E)

Abbreviation for Licentiate of the Royal College of Physicians (Edinburgh).

L.R.C.P.(I)
L.R.C.P.(I)

Abbreviation for Licentiate of the Royal College of Physicians (Ireland).

L.R.C.S.
L.R.C.S.

Abbreviation for Licentiate of the Royal College of Surgeons (of England).

L.R.C.S.(E)
L.R.C.S.(E)

Abbreviation for Licentiate of the Royal College of Surgeons (Edinburgh).

L.R.C.S.(I)
L.R.C.S.(I)

Abbreviation for Licentiate of the Royal College of Surgeons (Ireland).

LRF
LRF

Abbreviation for luteinizing hormone-releasing factor.

L.R.F.P.S.
L.R.F.P.S.

Abbreviation for Licentiate of the Royal Faculty of Physicians and Surgeons, a Scottish institution.

LRH
LRH

Abbreviation for luteinizing hormone-releasing hormone.

LSA
LSA

Abbreviation for left sacroanterior position.

LSD
LSD

Abbreviation for lysergic acid diethylamide.

LSF
LSF

Abbreviation for line spread function.

LSIL
LSIL

Abbreviation for low-grade squamous intraepithelial lesion.

LSP
LSP

Abbreviation for left sacroposterior position.

LST
LST

Abbreviation for left sacrotransverse position.

LT
LT

Abbreviation for leukotrienes, usually followed by another letter with a subscript number; e.g., LTA₄, LTC₄.

LTM
LTM

Abbreviation for long-term memory.

LTP LTP

Abbreviation for laser trabeculoplasty.

LTR
LTR

Abbreviation for long terminal repeat sequences, under sequence.

Lu
Lu

Symbol for lutetium.

Lubarsch
Lubarsch

Otto, German pathologist, 1860–1933. See L. crystals, under crystal.

Luc
Luc

Henri, French laryngologist, 1855–1925. See L. operation, Caldwell-L. operation, Ogston-L. operation.

lucanthone hydrochloride
lucanthone hydrochloride (loo-kan′thon)

Used in the treatment of urinary schistosomiasis (Schistosoma haematobium) and intestinal schistosomiasis (S. mansoni).

Lucas
Lucas

Richard C., English anatomist and surgeon, 1846–1915. See L. groove.

lucensomycin
lucensomycin (loo-sen-so-mi′sin)

An antibiotic isolated from cultures of Streptomyces lucensis; an antifungal agent. SYN: lucimycin.

lucent
lucent (loo′sent)

Bright; clear; translucent. [L. luceo, to shine]

lucid
lucid (loo′sid)

Clear, not obscured or confused, as in a l. moment or l. spoken expression. [L. lucidus, clear]

lucidification
lucidification (loo-sid′i-fi-ka′shun)

SYN: clarification. [L. lucidus, clear, + facio, to make]

lucidity
lucidity (loo-sid′i-te)

The quality or state of being lucid.

luciferases
luciferases (loo-sif′er-as-ez)

Enzymes present in certain luminous organisms that act to bring about the oxidation of luciferins; energy produced in the process is liberated as bioluminescence; such enzymes can be used to detect very low concentrations of metabolites.

luciferins
luciferins (loo-sif′er-inz)

Chemical substances present in certain luminous organisms that, when acted upon by luciferases, produce bioluminescence. [L. lux, light + fero. to bear]

lucifugal
lucifugal (loo-sif′u-gal)

Avoiding light. [L. lux, light, + fugio, to flee from]

Lucilia
Lucilia (loo-sil′e-a)

A genus of scavenging blowflies (family Calliphoridae), commonly called bluebottle or greenbottle flies, whose larvae feed on carrion or excrement; they occasionally cause wound infestation or myiasis.
L. caesar a species whose larvae formerly were used in the treatment of septic wounds. SEE ALSO: Phormia regina.
L. illustris a metallic blue-green blowfly widely distributed in North America; the eggs are deposited chiefly on animal carcasses.
L. sericata SYN: Phaenicia sericata.

lucimycin
lucimycin (loo-si-mi′sin)

SYN: lucensomycin.

Lucio
Lucio

R., Mexican physician, 1819–1866. See L. leprosy, L. leprosy phenomenon.

lucipetal
lucipetal (loo-sip′i-tal)

Seeking light. [L. lux, light, + peto, to seek]

Lucké
Lucké

Balduin, U.S. pathologist, 1889–1954. See Lucké virus.

Lücke
Lücke

George A., German surgeon, 1829–1894. See L. test.

lückenschädel
lückenschädel (luk-en-sha′dl)

Craniolacunia with meningocele or encephalocele. [Ger. Lücke, gap + Schädel, skull]

Ludwig
Ludwig

Daniel, German anatomist, 1625–1680. See L. angle.

Ludwig
Ludwig

Karl F.W., German anatomist and physiologist, 1816–1895. See depressor nerve of L., L. ganglion, L. labyrinth, L. nerve, L. stromuhr.

Ludwig
Ludwig

Kurt, German anatomist, *1922. See Klinger-L. acid-thionin stain for sex chromatin.

Ludwig
Ludwig

Wilhelm Friedrich von, German surgeon, 1790–1865. See L. angina.

Luebering
Luebering

J. See Rapoport-L. shunt.

Luer
Luer

German instrument maker, &dag;1883. See L. syringe, L.-Lok syringe.

lues
lues (loo′ez)

A plague or pestilence; specifically, syphilis. [L. pestilence]
l. venerea SYN: syphilis.

luetic
luetic (loo-et′ik)

SYN: syphilitic.

Luft
Luft

John H., U.S. histologist, *1927. See L. potassium permanganate fixative.

Luft
Luft

Rolf, Swedish endocrinologist, *1914. See L. disease.

Lugol
Lugol

Jean G.A., French physician, 1786–1851. See L. iodine solution.

Lukes
Lukes

L.J., 20th century U.S. pathologist. See L.-Collins classification.

Lukes-Collins classification
Lukes-Collins classification

See under classification.

LUL
LUL

Abbreviation for left upper lobe (of lung).

luliberin
luliberin (loo-lib′er-in)

A decapeptide hormone from the hypothalamus that stimulates the anterior pituitary to release both follicle-stimulating hormone and luteinizing hormone; gonadotropin-releasing hormone. SYN: luteinizing hormone-releasing hormone. [luteinizing hormone + L. libero, to free, + -in]

lumbago
lumbago (lum-ba′go)

Pain in mid and lower back; a descriptive term not specifying cause. [L. fr. lumbus, loin]
ischemic l. an ischemic form of backache characterized by a painful cramp of the muscles in the lumbar region incited by the exertion of walking or standing and promptly relieved by rest.

lumbar
lumbar (lum′bar)

Relating to the loins, or the part of the back and sides between the ribs and the pelvis. [L. lumbus, a loin]

lumbarization
lumbarization (lum′bar-i-za′shun)

A congenital anomaly of the lumbosacral junction characterized by development of the first sacral vertebra as a lumbar vertebra, resulting in six lumbar vertebrae instead of five.

lumbi
lumbi (lum′bi)

Plural of lumbus. [L.]

lumboabdominal
lumboabdominal (lum′bo-ab-dom′i-nal)

Relating to the sides and front of the abdomen.

lumbocostal
lumbocostal (lum′bo-kos′tal)

1. Relating to the lumbar and the hypochondriac regions. 2. Relating to the lumbar vertebrae and the ribs; denoting a ligament connecting the first lumbar vertebra with the neck of the twelfth rib. [L. lumbus, loin, + costa, rib]

lumboiliac
lumboiliac (lum-bo-il′e-ak)

SYN: lumboinguinal.

lumboinguinal
lumboinguinal (lum′bo-ing′gwi-nal)

Relating to the lumbar and the inguinal regions. SYN: lumboiliac. [L. lumbus, loin, + inguen (inguin-), groin]

lumbo-ovarian
lumbo-ovarian (lum-bo-o-va′re-an)

Relating to the ovary and the lumbar regions.

lumbosacral
lumbosacral (lum′bo-sa′kral)

Relating to the lumbar vertebrae and the sacrum. SYN: sacrolumbar.

lumbrical
lumbrical (lum′bri-kal)

SYN: lumbricoid (1) . [L. lumbricus, earthworm]

lumbricalis
lumbricalis

See lumbricals (lumbrical muscles) of hand, under muscle, lumbricals (lumbrical muscles) of foot, under muscle.

lumbricidal
lumbricidal (lum-bri-si′dal)

Destructive to lumbricoid (intestinal) worms.

lumbricide
lumbricide (lum′bri-sid)

An agent that kills lumbricoid (intestinal) worms. [L. lumbricus, worm, + caedo, to kill]

lumbricoid
lumbricoid (lum′bri-koyd)

1. Denoting or resembling a roundworm, especially Ascaris lumbricoides. SYN: lumbrical, lumbricus (1) . SEE ALSO: scolecoid (2) , vermiform. 2. Obsolete common name for Ascaris lumbricoides. [L. lumbricus, earthworm, + G. eidos, resemblance]

lumbricosis
lumbricosis (lum′bri-ko′sis)

Infection with round intestinal worms.

lumbricus
lumbricus (lum′bri-kus)

1. SYN: lumbricoid (1) . 2. Obsolete name for Ascaris lumbricoides. [L. earthworm]

lumbus
lumbus, gen. and pl. lumbi (lum′bus, -bi)

SYN: loin. [L.]

lumen
lumen, pl .luminalumens (loo′men, -min-a, -menz)

1. The space in the interior of a tubular structure, such as an artery or the intestine. 2. (lm) The unit of luminous flux; the luminous flux emitted in a unit solid angle of 1 steradian by a uniform point source of light having a luminous intensity of 1 candela. 3. The volume enclosed within the membranes of a mitochondrion or of the endoplasmic reticulum. 4. The bore of a catheter or hollow needle. [L. light, window]
false l. in a dissecting aneurysm, the abnormal channel within the wall of the involved artery.
residual l. SYN: residual cleft.
true l. in a dissecting aneurysm, the channel representing the actual intima-lined artery.

lumichrome
lumichrome (loo′mi-krom)

7,8-Dimethylalloxazine;riboflavin minus its ribityl side chain; produced by ultraviolet irradiation of riboflavin in acid solution.

lumiflavin
lumiflavin (loo′mi-fla-vin)

7,8,10-Trimethylisoalloxazine;a yellow photoderivative of riboflavin, bearing a methyl group in place of the ribityl; produced by ultraviolet irradiation of riboflavin in alkaline solution.

lumina
lumina (loo′mi-na)

Plural of lumen. [L.]

luminal
luminal (loo′mi-nal) [TA]

Relating to the lumen of a blood vessel or other tubular structure. SYN: luminalis [TA] .

luminalis
luminalis [TA]

SYN: luminal.

luminance
luminance (loo′mi-nans)

The brightness of an object, expressed as the luminous flux per unit solid angle per unit projected area, measured in lamberts or in candelas per square meter. [L. lumino, to light up, fr. lumen, light]

luminescence
luminescence (loo-mi-nes′ens)

Emission of light from a body as a result of a chemical reaction. See bioluminescence. [L. lumen, light]

luminiferous
luminiferous (loo-mi-nif′er-us)

Producing or conveying light. [L. lumen, light, + fero, to carry]

luminophore
luminophore (loo′mi-no-for)

An atom or atomic grouping in an organic compound that increases its ability to emit light. [L. lumen, light, + G. phoros, bearing]

luminous
luminous (loo′mi-nus)

Emitting light, with or without accompanying heat. [L. lumen, light]

lumirhodopsin
lumirhodopsin (loo′mi-ro-dop′sin)

An intermediate between rhodopsin and all-trans-retinal plus opsin during bleaching of rhodopsin by light; formed from bathorhodopsin and converted to metarhodopsin I with a half-life of about 20 μs. [L. lumen, light, + G. rhodon, rose, + opsis, vision]

lumisterol
lumisterol (loom-e-ster′ol)

1. A by-product in ergocalciferol biosynthesis. 2. A phosphorylated derivative of ribulose that is an intermediate in the pentose monophosphate shunt.

lumpectomy
lumpectomy (lum-pek′to-me)

Removal of either a benign or malignant lesion from the breast with preservation of essential anatomy of the breast; tylectomy involving breast tissue. [lump + G. ektome, excision]

Luna
Luna

Lee G., 20th century U.S. medical technologist. See L.-Ishak stain.

lunacy
lunacy (loo′na-se)

1. An obsolete term for a form of insanity characterized by alternating lucid and insane periods, believed to be influenced by phases of the moon. 2. Any form of insanity. 3. Insanity as defined variously by law. [L. luna, moon]

lunar
lunar (loo′ner)

1. Relating to the moon or to a month. 2. Resembling the moon in shape, especially a half moon. SYN: lunate (1) [TA] , semilunar. SEE ALSO: crescentic. 3. Relating to silver (the moon was the symbol of silver in alchemy). [L. luna, moon]

lunar caustic
lunar caustic

SYN: toughened silver nitrate.

lunare
lunare (loo-na′re)

SYN: lunate (bone).

lunate
lunate (loo′nat) [TA]

1. SYN: lunar (2) . 2. Relating to the l. bone.

lunatic
lunatic (loo′na-tik)

Obsolete term for a mentally ill person. [see lunacy]

lunatomalacia
lunatomalacia (loo-na′to-ma-la′she-a)

SYN: Kienböck disease.

lung
lung (lung) [TA]

One of a pair of viscera occupying the pulmonary cavities of the thorax, the organs of respiration in which aeration of the blood takes place. In humans, the right l. is slightly larger than the left and is divided into three lobes (an upper, a middle, and a lower or basal), while the left has but two lobes (an upper and a lower or basal). Each l. is irregularly conical in shape, presenting a blunt upper extremity (the apex), a concave base following the curve of the diaphragm, an outer convex surface (costal surface), a generally concave inner or medial surface (mediastinal surface), a thin and sharp anterior border, and a rounded posterior border. SYN: pulmo [TA] . [A.S. lungen]
air-conditioner l. an extrinsic allergic alveolitis caused by forced air contaminated by thermophilic actinomycetes and other organisms.
bird-breeder's l., bird-fancier's l. extrinsic allergic alveolitis caused by inhalation of particulate avian emanations; sometimes specified by avian species, e.g., pigeon-breeder's l., budgerigar-breeder's l.. SYN: bird-breeder's disease.
black l. a form of pneumoconiosis, common in coal miners, characterized by deposits of carbon particles in the l.. SYN: miner's l. (2) .
brown l. obstructive airway disease with asthma produced by exposure to cotton dust, flax, or hemp. SEE ALSO: byssinosis.
butterfly l. hemorrhagic markings appearing on an animal's l. after inoculation with Leptospira interrogans (L. icterohaemorrhagiae).
cardiac l. disturbance in pulmonary anatomy and physiology secondary to valvular disease of the heart or to other disturbances of circulation incident to cardiac disease.
cheese worker's l. extrinsic allergic alveolitis caused by inhalation of spores of Penicillium casei from moldy cheese.
collier l. SYN: anthracosis.
cystic l. SYN: honeycomb l..
endstage l. severe diffuse interstitial fibrosis and honeycombing.
farmer's l. a hypersensitivity pneumonitis characterized by fever and dyspnea, caused by inhalation of organic dust from moldy hay containing spores of thermophilic actinomycetes such as Micromonospora vulgaris, M. faeni, and Thermopolyspora polyspora, which thrive in the elevated temperatures of hay lofts and silos; repeated exposure may result in alveolar sensitization and, ultimately, granulomatous l. disease with severe disability. SYN: thresher's l..
fibroid l. chronic interstitial pneumonia in a l..
honeycomb l. the radiologic and gross appearance of the lungs resulting from interstitial fibrosis and cystic dilation of bronchioles and distal air spaces; of unknown cause or a sequel of any of several diseases, including eosinophilic granuloma, sarcoidosis, and any interstitial l. disease. SYN: cystic l..
hyperlucent l. the radiographic finding that a l. or portion thereof is less dense than normal, as from air trapping by a bronchial foreign body, asymmetric emphysema, or decreasing blood flow. See unilateral hyperlucent l..
iron l. SYN: Drinker respirator.
malt-worker's l. extrinsic allergic alveolitis caused by inhalation of spores of Aspergillus clavatus and A. fumigatus from contaminated barley during the manufacture of beer.
mason's l. silicosis occurring in stone masons.
miner's l. 1. SYN: anthracosis. 2. SYN: black l..
mushroom-worker's l. extrinsic allergic alveolitis caused by inhalation of spores of the mold Thermopolyspora polyspora or Micromonospora vulgaris from contaminated mushrooms under cultivation.
postperfusion l. a condition in which abnormal pulmonary function develops in patients who have undergone cardiac surgery involving the use of an extracorporeal circulation; now rare due to advances in perfusion technique and equipment.
pump l. SYN: shock l..
quiet l. the collapse of a l. during thoracic operations undertaken to facilitate surgical procedure through absence of l. movement.
shock l. in shock, the development of edema, impaired perfusion, and reduction in alveolar space so that the alveoli collapse. SYN: pump l., wet l. (1) , white l..
silo-filler's l. pulmonary edema, usually delayed for 1–4 hours, occurring in an individual exposed to silage, probably due to nitrogen dioxide; can progress to bronchiolitis obliterans.
thresher's l. SYN: farmer's l..
unilateral hyperlucent l. chronic bronchiolitis obliterans predominating on one side. See unilateral lobar emphysema. SEE ALSO: Swyer-James syndrome (2) .
uremic l. perihilar edema of the l. associated with renal failure and hypertension; the peripheral parts of the l. remain clear. SYN: uremic pneumonia (1) , uremic pneumonitis.
vanishing l. vanishing l. syndrome.
welder's l. relatively benign form of pneumoconiosis, associated with welding, resulting from deposit of fine metallic particles in the l..
wet l., white l. 1. SYN: shock l.. 2. SYN: adult respiratory distress syndrome.

lungworms
lungworms (lung′wermz)

Nematodes that inhabit the air passages of animals, chiefly in the family Metastrongylidae (or Protostrongylidae). See Aelurostrongylus, Crenosoma vulpis, Metastrongylus, Muellerius capillaris.

lunula
lunula, pl .lunulae (loo′noo-la, -le) [TA]

1. [NA] The pale arched area at the proximal portion of the nail plate. 2. A small semilunar structure. [L. dim. of luna, moon]
azure l. of nails bluish nonblanching discoloration of the lunulae of all the fingernails in hepatolenticular degeneration.
l. of semilunar cusps of aortic/pulmonary valves the free border of a cusp of the semilunar valves on each side of the nodules of the semilunar cusps. SYN: l. of semilunar valve, lunulae valvularum semilunarium valvae aortae/trunci pulmonalis.
l. of semilunar valve SYN: l. of semilunar cusps of aortic/pulmonary valves.
l. unguis SYN: lunule of nail.
lunulae valvularum semilunarium valvae aortae/trunci pulmonalis SYN: l. of semilunar cusps of aortic/pulmonary valves.

lunule
lunule

1. [TA] SYN: l. of nail. 2. A small semilunar structure.
l. of nail the pale arched area at the proximal portion of the nail plate. SYN: arcus unguium, half-moon, lunula unguis, l. (1) , selene unguium.

lupinidine
lupinidine (loo-pin′i-den)

SYN: sparteine.

lupinosis
lupinosis (loo-pi-no′sis)

SYN: lathyrism. [L. lupinus, lupine, fr. lupus, wolf]

lupoid
lupoid (loo′poyd)

Resembling lupus. [L. lupus + G. eidos, resemblance]

lupulin
lupulin (loo′poo-lin)

A sticky, yellowish, granular material consisting of entire multicellular glandular hairs (trichomes) from the fruit and bracts of the hop vine, Humulus lupulus; the essential oils and resins of these glandular hairs are responsible for the characteristic bitter taste of beer or medicinals made from hops; has been used as an antispasmodic and sedative. SYN: humulin.

lupus
lupus (loo′pus)

A term originally used to depict erosion (as if gnawed) of the skin, now used with modifying terms designating the various diseases listed below. [L. wolf]
chilblain l. 1. SYN: chilblain l. erythematosus. 2. l. pernio that is a manifestation of sarcoidosis.
chilblain l. erythematosus skin lesions seen in patients with l. erythematosus, resembling the small, hardened nodular areas of a cold injury called chilblains. SYN: chilblain l. (1) .
chronic discoid l. erythematosus SYN: discoid l. erythematosus.
cutaneous l. erythematosus 1. skin disease seen in patients with discoid form of l. erythematosus; 2. a term for a variety of skin lesions seen in systemic l. erythematosus.
discoid l. erythematosus a form of l. erythematosus in which cutaneous lesions are present; these commonly appear on the face and are atrophic plaques with erythema, hyperkeratosis, follicular plugging, and telangiectasia; in some instances systemic l. erythematosis may develop. SYN: chronic discoid l. erythematosus.
disseminated l. erythematosus SYN: systemic l. erythematosus.
drug-induced l. the syndrome of systemic l. erythematosus induced by exposure to drugs, especially procainamide or hydralazine and characterized by antihistone antibodies. More benign than the usual disease, with less renal involvement. The syndrome clears after stopping the offending drug. SYN: hydralazine syndrome.
l. erythematosus (LE, L.E.) an illness that may be chronic (characterized by skin lesions alone), subacute (characterized by recurring superficial nonscarring skin lesions that are more disseminated and present more acute features both clinically and histologically than those seen in the chronic discoid phase), or systemic or disseminated (in which antinuclear antibodies are present and in which there is almost always involvement of vital structures). SEE ALSO: discoid l. erythematosus, systemic l. erythematosus.
l. erythematosus, neonatal l. erythematosus present at birth as a result of placentally transmitted antibodies from a mother with systemic l. erythematosus; characterized by transient hematopoietic and cutaneous lesions and permanent cardiac abnormalities.
l. erythematosus profundus a subcutaneous panniculitis with marked lymphocyte infiltration of fat lobules giving rise to deep-seated, firm, rubbery nodules that sometimes become ulcerated, usually of the face; may occur in systemic and localized l. erythematosus. SYN: l. profundus.
l. livedo persistent cyanotic lesions on the extremities, associated with the cutaneous manifestations of Raynaud disease.
l. miliaris disseminatus faciei a milletlike papular eruption of the face associated with a (histopathologically) tuberculoid perifollicular infiltration but probably related to rosacea rather than tuberculous infection.
neonatal l. l. erythematosus occurring in newborn children of mothers who had l. during pregnancy; anti-SSA antibodies usually should be screened for; 50% have anti-nuclear antibodies. A variety of skin lesions are seen, which can resolve or leave scarring; the syndrome usually resolves; however, cardiac manifestations can be fatal. Some children develop systemic l. later in life.
l. pernio chronic indurated purple granulomatous skin of sarcoidosis lesion, clinically resembling frostbite, involving ears, cheeks, nose, lips, and forehead; usually with intrathoracic sarcoidosis.
l. profundus (pro-fun′dus) SYN: l. erythematosus profundus. [L. deep]
l. serpiginosus a cutaneous tuberculous lesion that spreads peripherally, healing centrally with scar formation.
systemic l. erythematosus (SLE) an inflammatory connective tissue disease with variable features, frequently including fever, weakness and fatigability, joint pains or arthritis resembling rheumatoid arthritis, diffuse erythematous skin lesions on the face, neck, or upper extremities, with liquefaction degeneration of the basal layer and epidermal atrophy, lymphadenopathy, pleurisy or pericarditis, glomerular lesions, anemia, hyperglobulinemia, and a positive LE cell test, with serum antibodies to nuclear protein and sometimes to double-stranded DNA and other substances. SYN: disseminated l. erythematosus.
l. vulgaris cutaneous tuberculosis with characteristic nodular lesions on the face, particularly about the nose and ears.

LUQ
LUQ

Abbreviation for left upper quadrant (of abdomen).

lura
lura (loo′ra)

The contracted termination of the infundibulum of the brain. [L. the mouth of a bottle]

lural
lural (loo′ral)

Pertaining to the lura.

Luschka
Luschka

Hubert, German anatomist, 1820–1875. See L. bursa, L. cartilage, L. ducts, under duct, L. gland, L. cystic glands, under gland, L. joints, under joint, L. ligaments, under ligament, L. sinus, L. tonsil, foramen of L..

Luse
Luse

Sarah A., U.S. physician, 1918–1970. See L. bodies, under body.

lusitropic
lusitropic (loos-e-tro′pik)

Relating to lusitropy.

lusitropy
lusitropy (loos-it′tro-pe)

Relaxation functions of cardiac muscle and chambers.

lute
lute (loot)

To seal or fasten with wax or cement. [L. lutum, mud]

luteal
luteal (loo′te-al)

Relating to the corpus luteum; l. cells, l. hormone, etc. SYN: luteus. [L. luteus, saffron-yellow]

lutecium
lutecium (loo-te′se-um)

SYN: lutetium.

lutein
lutein (loo′te-in)

1. The yellow pigment in the corpus luteum, in the yolk of eggs, or any lipochrome. 2. SYN: xanthophyll. 3. The dried powdered corpora lutea of the hog, formerly used as a progesterone source. [L. luteus, saffron-yellow]

luteinization
luteinization (loo′te-in-i-za′shun)

Transformation of the mature ovarian follicle and its theca interna into a corpus luteum after ovulation; formation of luteal tissue, which appears yellow in some species.

luteinize
luteinize (loo′te-i-niz)

To form luteal tissue.

luteinoma
luteinoma (loo′te-i-no′ma)

SYN: luteoma.

Lutembacher
Lutembacher

René, French cardiologist, 1887–1916. See L. syndrome.

luteogenic
luteogenic (loo′te-o-jen′ik)

Luteinizing; inducing the production or growth of corpora lutea.

luteohormone
luteohormone (loo′te-o-hor′mon)

SYN: progesterone.

luteol
luteol, luteole (loo′te-ol, -ol)

SYN: xanthophyll.

luteolin
luteolin (loo-te-o′lin)

The aglycon of galuteolin and cynaroside. SYN: cyanidenon.

luteolysin
luteolysin (loo-te-ol′i-sin)

Any agent, natural or compounded, that destroys the function of the corpus luteum. [L. luteus, saffron-yellow, + G. lysis, dissolution]

luteolysis
luteolysis (loo-te-ol′i-sis)

Degeneration or destruction of ovarian luteinized tissue.

luteolytic
luteolytic (loo-te-o-lit′ik)

Promoting or characteristic of luteolysis.

luteoma
luteoma (loo-te-o′ma)

An ovarian tumor of granulosa or theca-lutein cell origin, producing progesterone effects on the uterine mucosa. SYN: luteinoma.
pregnancy l. a benign lutein cell tumor of the ovary.

luteotropic
luteotropic, luteotrophic (loo′te-o-trop′ik, -trof′ik)

Having a stimulating action on the development and function of the corpus luteum.

lutetium
lutetium (Lu) (loo-te′she-um)

A rare earth element; atomic no. 71, atomic wt. 174.967. SYN: lutecium. [L. Lutetia, Paris]

luteus
luteus (loo-te′us)

SYN: luteal. [L.]

Lutheran Blood Group
Lutheran Blood Group, Lu Blood Group

See Blood Groups Appendix.

lutropin
lutropin (loo′tro-pin)

One of two glycoprotein hormones that stimulate the final ripening of the follicles and the secretion of progesterone by them, their rupture to release the egg, and the conversion of the ruptured follicle into the corpus luteum. SYN: interstitial cell-stimulating hormone, luteinizing hormone, luteinizing principle.

lututrin
lututrin (loo′too-trin)

A water-soluble protein-like fraction extracted from the corpus luteum of sows' ovaries, resembling relaxin; it causes uterine relaxation and is used in dysmenorrhea.

Lutz
Lutz

Alfredo, Brazilian physician, 1855–1940. See L.-Splendore-Almeida disease.

Lutzomyia
Lutzomyia (loot-zo-mi′a)

A genus of New World sandflies or bloodsucking midges (family Psychodidae) that serve as vectors of leishmaniasis and Oroyo fever; formerly combined with the Old World sandfly genus Phlebotomus.
L. flaviscutellata a sandfly species that is a vector of Leishmania mexicana, the agent of chiclero ulcer. SYN: Phlebotomus flaviscutellatus.
L. intermedius one of a group of sandfly species that are vectors of Leishmania braziliensis, the agent of espundia.
L. longipalpis SYN: Phlebotomus longipalpis.
L. peruensis a sandfly species that is a vector of Leishmania peruviana, the agent of uta.

lux
lux (lx) (luks)

A unit of light or illumination; the reception of a luminous flux of 1 lumen per square meter of surface. SYN: candle-meter, meter-candle. [L. light]

luxatio
luxatio (luk-sa′she-o)

See luxation. [L. luxo, pp. -atus, to dislocate]
l. erecta subglenoid dislocation of the head of the humerus in which the arm is raised and abducted and cannot be lowered.
l. perinealis a condition in which the head of the femur is dislocated to the perineum.

luxation
luxation (luk-sa′shun)

1. SYN: dislocation. 2. In dentistry, the dislocation or displacement of the condyle in the temporomandibular fossa, or of a tooth from the alveolus. [L. luxatio]
Malgaigne l. SYN: nursemaid's elbow.

Luxol fast blue
Luxol fast blue

Name for a group of closely related copper phthalocyanin dyes used as stains (with PAS, PTAH, hematoxylin, silver nitrate, etc.) for myelin in nerve fibers.

luxus
luxus (luks′us)

Excess of any sort. [L. extravagance, luxury]

Luys
Luys

Jules Bernard, French physician, 1828–1897. See L. body, centre médian de L., corpus luysi, nucleus of L..

LVET
LVET

Abbreviation for left ventricular ejection time.

L.V.N.
L.V.N.

Abbreviation for licensed vocational nurse.

Lw
Lw

Former symbol for lawrencium.

lx
lx

Abbreviation for lux.

lyase
lyase (li′as)

Class name for those enzymes removing groups nonhydrolytically (EC class 4); prefixes such as “hydro-” and “ammonia-” are used to indicate the type of reaction. Trivial names for lyases include synthases, decarboxylases, aldolases, dehydratases. Cf.:synthase, synthetase.

lycanthropy
lycanthropy (li-kan′thro-pe)

The morbid delusion that one is a wolf, possibly a mental atavism of the werewolf superstition. [G. lykos, wolf, + anthropos, man]

lycoctonine
lycoctonine (li-kok′to-nen)

An alkaloid, C₂₅H₄₁NO₇, obtained from Aconitum lycoctonum, an exceedingly poisonous species of aconite; it also occurs in other species of Aconitum and Delphinium.

lycopene
lycopene (li′ko-pen)

Ψ,Ψ-Carotene;the characteristic red pigment of the tomato that may be considered chemically as the parent substance from which all natural carotenoid pigments are derived; an unsaturated hydrocarbon made up of eight isoprene units, two of them hydrogenated, with 11 conjugated double bonds.

lycopenemia
lycopenemia (li′ko-pe-ne′me-a)

A condition in which there is a high concentration of lycopene in the blood, producing carotenoidlike yellowish pigmentation of the skin; found in people who consume excessive amounts of tomatoes or tomato juice, or lycopene-containing fruits and berries. [lycopene + G. haima, blood]

Lycoperdon
Lycoperdon (liko-per′don)

A genus of fungi (family Lycoperdaceae), some species of which have been used medicinally, e.g., in folk medicine, by nasal inhalation to treat epistaxis. The spores of L. bovista (L. gemmatum, L. caelatum) and of L. pyriforme may rarely produce lycoperdonosis. SYN: puffball. [G. lykos, wolf, + perdomai, to break wind]

lycoperdonosis
lycoperdonosis (li′ko-per-don-o′sis)

A persisting pneumonitis following inhalation of spores of the puffballs Lycoperdon pyriforme and L. bovista.

lycophora
lycophora (li-kof′o-ra)

The 10-hooked larva of primitive tapeworms of the subclass Cestodaria.

lycopodium
lycopodium (li-ko-po′de-um)

The spores of L. clavatum (family Lycopodiaceae) and other species of L.; a yellow, tasteless, and odorless powder; was used as a dusting powder and in pharmacy to prevent the agglutination of pills in a box. SYN: club moss, vegetable sulfur. [G. lykos, wolf, + pous, foot]

lye
lye (li)

The liquid obtained by leaching wood ashes. See potassium hydroxide, sodium hydroxide. SYN: lixivium. [A.S. leáh]

Lyell
Lyell

Aian. See L. disease, L. syndrome.

Lymnaea
Lymnaea (lim-ne′a)

A genus of snails, species of which are invertebrate hosts for the liver or sheep liver fluke, Fasciola hepatica, and other trematodes. [G. limne, marsh]

lymph
lymph (limf) [TA]

A clear, transparent, sometimes faintly yellow and slightly opalescent fluid that is collected from the tissues throughout the body, flows in the lymphatic vessels (through the l. nodes), and is eventually added to the venous blood circulation. L. consists of a clear liquid portion, varying numbers of white blood cells (chiefly lymphocytes), and a few red blood cells. SYN: lympha [TA] . [L. lympha, clear spring water]
aplastic l. l. containing a relatively large number of leukocytes, but comparatively little fibrinogen; such l. does not form a good clot and manifests only a slight tendency to become organized. SYN: corpuscular l..
blood l. l. exuded from the blood vessels and not derived from the fluid in the tissue spaces.
corpuscular l. SYN: aplastic l..
croupous l. a form of inflammatory l. with an unusually large content of fibrinogen; as a result of the fibrin that is formed in relatively dense mats, a pseudomembrane is likely to be produced.
dental l. SYN: dentinal fluid.
euplastic l. l. that contains relatively few leukocytes, but a comparatively high concentration of fibrinogen; such l. clots fairly well and tends to become organized with fibrous tissue.
fibrinous l. a euplastic or croupous l..
inflammatory l. a faintly yellow, usually coagulable fluid ( i.e., euplastic l.) that collects on the surface of an acutely inflamed membrane or cutaneous wound.
intercellular l. the fluid in the potential spaces between cells in the various organs and tissues.
intravascular l. l. within the lymphatic vessels, in contrast to intercellular l. and l. that has exuded from the vessels.
plastic l. inflammatory l. that has a tendency to become organized.
tissue l. true l., i.e., l. derived chiefly from fluid in tissue spaces (in contrast to blood l.).
vaccine l., vaccinia l. that collected from the vesicles of vaccinia infection, and used for active immunization against smallpox.

lymph- lymph-

See lympho-.

lympha
lympha (lim′fa) [TA]

SYN: lymph. [L.]

lymphaden
lymphaden (limf′a-den)

SYN: lymph node. [lymph- + G. aden, gland]

lymphaden- lymphaden-

See lymphadeno-.

lymphadenectomy
lymphadenectomy (lim-fad-e-nek′to-me)

Excision of lymph nodes. [lymphadeno- + G. ektome, excision]

lymphadenitis
lymphadenitis (lim′-fad′e-ni′tis)

Inflammation of a lymph node or lymph nodes. [lymphadeno- + G. -itis, inflammation]
dermatopathic l. SYN: dermatopathic lymphadenopathy.
mesenteric l. SYN: mesenteric adenitis.
paratuberculous l. old term for chronic inflammation of certain lymph nodes, not specifically tuberculous ( i.e., tubercle bacilli are not demonstrable), but associated with proved tuberculous inflammation in another part or organ of the body.
regional l. inflammation of a group of lymph nodes receiving drainage from a site of infection.
regional granulomatous l. SYN: catscratch disease.
tuberculosis l. SYN: tuberculous l..
tuberculous l. l. resulting from infection by Mycobacterium tuberculosis; tuberculosis of the lymph nodes. SYN: tuberculosis l..

lymphadeno- lymphadeno-, lymphaden-

The lymph nodes. [L. lympha, spring water, + G. aden, gland]

lymphadenography
lymphadenography (lim-fad′e-nog′ra-fe)

Radiographic visualization of lymph nodes after injection of a contrast medium; lymphography. [lymphadeno- + G. grapho, to write]

lymphadenoid
lymphadenoid (lim-fad′e-noyd)

Relating to, or resembling, or derived from a lymph node. [lymphadeno- + G. eidos, resemblance]

lymphadenoma
lymphadenoma (lim-fad′e-no′ma)

Obsolete term for: 1. An enlarged lymph node. 2. SYN: Hodgkin disease. [lymphadeno- + G. -oma, tumor]

lymphadenopathy
lymphadenopathy (lim-fad-e-nop′a-the)

Any disease process affecting a lymph node or lymph nodes. [lymphadeno- + G. pathos, suffering]
angioimmunoblastic l. with dysproteinemia (AILD) a lymphoproliferative disorder characterized by generalized l., hepatosplenomegaly, fever, sweats, weight loss, skin lesions, and pruritus with hypergammaglobulinemia; occurs primarily in older adults, often with fatal outcome. Proliferation of B cells, deficiency of T cells have been demonstrated. SYN: immunoblastic l..
bulky l. SYN: bulky disease.
dermatopathic l. enlargement of lymph nodes, with proliferation of pale-staining interdigitating reticulum cells and macrophages containing fat and melanin; secondary to various forms of dermatitis. SYN: dermatopathic lymphadenitis.
immunoblastic l. SYN: angioimmunoblastic l. with dysproteinemia.
persistent generalized l. a syndrome characterized by reactive hyperplasia of lymph nodes (of at least one month's duration and at two different body sites, not including the inguinal area) in patients infected with the human immunodeficiency virus. The lymph node lesions progress from benign reactive hyperplasia through a stage of mixed follicular hyperplasia, to follicular involution with lymphocyte depletion. Many go on to a malignant non-Hodgkin lymphoma.

lymphadenosis
lymphadenosis (lim-fad′e-no′sis)

The basic underlying proliferative process that results in enlargement of lymph nodes, as in lymphocytic leukemia and certain inflammations. [lymphadeno- + G. -osis, condition]
benign l. SYN: infectious mononucleosis.

lymphadenovarix
lymphadenovarix (lim-fad′e-no-va′riks)

Varicose deformity of a lymph node associated with lymphangiectasis. [lymphadeno- + L. varix]

lymphagogue
lymphagogue (limf′a-gog)

An agent that increases the formation and flow of lymph. [lymph + G. agogos, drawing forth]

lymphangeitis
lymphangeitis (lim-fan′je-i′tis)

SYN: lymphangitis.

lymphangi- lymphangi-

See lymphangio-.

lymphangial
lymphangial (lim-fan′je-al)

Relating to a lymphatic vessel.

lymphangiectasis
lymphangiectasis, lymphangiectasia (lim-fan′je-ek′ta-sis, -ek-ta′ze-a)

Dilation of the lymphatic vessels, the basic process that may result in the formation of a lymphangioma. SYN: lymphectasia, telangiectasia lymphatica. [lymphangio- + G. ektasis, a stretching]
cavernous l. SYN: lymphangioma cavernosum.
cystic l. SYN: lymphangioma cysticum.
intestinal l. [MIM*152800] familial l. with intestinal loss of lymph causing lymphocytopenia and hypogammaglobulinemia.
simple l. SYN: lymphangioma simplex.

lymphangiectatic
lymphangiectatic (lim-fan′je-ek-tat′ik)

Relating to or characterized by lymphangiectasis.

lymphangiectomy
lymphangiectomy (lim-fan′je-ek′to-me)

Excision of a lymph channel. [lymphangio- + G. ektome, excision]

lymphangiitis
lymphangiitis (lim-fan′je-i′tis)

SYN: lymphangitis.

lymphangio- lymphangio-, lymphangi-

The lymphatic vessels. [L. lympha, spring water, + G. angeion, vessel]

lymphangioendothelioma
lymphangioendothelioma (lim-fan′je-o-en′do-the-le-o′ma)

Old term for combined lymphatico-venous malformation. [lymphangio- + endothelium + -oma, tumor]

lymphangiography
lymphangiography (lim-fan′je-og′ra-fe)

Radiographic demonstration of lymphatics and lymph nodes following the injection of a contrast medium; lymphography. [lymphangio- + G. grapho, to write]

lymphangioleiomyomatosis
lymphangioleiomyomatosis

A rare disorder of unknown etiology seen in women of reproductive age and in patients of either sex with tuberous sclerosis. Pulmonary complications are due to hamartomatous proliferation of smooth muscle cells preferentially along bronchovascular structures resulting in obliteration of the airways and consecutive development of cysts in the lungs. Usually progressive, leading to death from respiratory failure. Treatment by lung transplantation has been successful. SYN: lymphangiomyomatosis.

lymphangiology
lymphangiology (lim-fan-je-ol′o-je)

The branch of medical science concerned with the lymphatic vessels. SYN: lymphology. [lymphangio- + G. logos, study]

lymphangioma
lymphangioma (lim-fan′je-o′ma)

Old term for a mass of anomalous lymphatic vessels or channels that vary in size, are usually greatly dilated, and are lined with normal endothelial cells; lymphoid tissue is usually present in the peripheral portions of the lesions, which are present at birth, or shortly thereafter, and probably represent maldevelopment of lymphatic vessels (rather than true neoplasms); they occur most frequently in the neck and axilla, but may also develop in the arm, mesentery, retroperitoneum, and other sites. [lymphangio- + G. -oma, tumor]
l. cavernosum a condition of conspicuous dilation of lymphatic vessels in a fairly circumscribed region, frequently with the formation of cavities or “lakes” filled with lymph. SYN: cavernous lymphangiectasis.
l. circumscriptum a congenital nevoid lesion consisting of a circumscribed group of tense lymph vesicles.
l. cysticum a condition characterized by a fairly well circumscribed group of several or numerous cystlike, dilated vessels or spaces lined with endothelium and filled with lymph. SYN: cystic lymphangiectasis.
l. simplex a circumscribed region or focus of several to numerous lymphatic vessels that are moderately dilated. SYN: simple lymphangiectasis.
l. tuberosum multiplex a cutaneous lesion characterized by multiple, slightly red, cystlike nodules (located chiefly on the trunk), resulting from fairly large lymphatic vessels and spaces, and groups of proliferating endothelial cells; the lesion has some gross resemblance to spiradenoma, except for the characteristic location.
l. xanthelasmoideum a capillary l. with colloid degeneration of the elastic tissues of the skin, characterized by yellow-brown or gray-brown plaques that may be only slightly raised above the surface of the skin.

lymphangiomatous
lymphangiomatous (lim-fan′je-o′ma-tus)

Pertaining to, characterized by, or containing lymphangioma.

lymphangiomyomatosis
lymphangiomyomatosis (lim-fan′ge-o-mi′o-ma-to′sis)

SYN: lymphangioleiomyomatosis. [lymphangio- + myoma + -osis, condition]

lymphangion
lymphangion (lim-fan′je-on)

A lymphatic vessel. See lymph vessels, under vessel. [L. lympha, lymph, + G. angeion, vessel]

lymphangiophlebitis
lymphangiophlebitis (lim-fan′je-o-fle-bi′tis)

Inflammation of the lymphatic vessels and veins.

lymphangioplasty
lymphangioplasty (lim-fan′je-o-plas-te)

Surgical alteration of lymphatic vessels. [lymphangio- + G. plastos, formed]

lymphangiosarcoma
lymphangiosarcoma (lim-fan′je-o-sar-ko′ma)

A malignant neoplasm derived from vascular tissue, i.e., an angiosarcoma, in which the neoplastic cells originate from the endothelial cells of lymphatic vessels, usually developing in the arm several years after radical mastectomy.

lymphangiotomy
lymphangiotomy (lim-fan′je-ot′o-me)

Incision of lymphatic vessels. [lymphangio- + G. tome, incision]

lymphangitis
lymphangitis (lim-fan-ji′tis)

Inflammation of the lymphatic vessels. SYN: lymphangeitis, lymphangiitis. [lymphangio- + G. -itis, inflammation]
l. carcinomatosa extensive lymphatic permeation by tumor cells, with surrounding fibrosis, producing visible or palpable cords, especially in pleura or skin overlying a carcinoma.

lymphapheresis
lymphapheresis (lim′fa-fe-re′sis)

SYN: lymphocytapheresis.

lymphatic
lymphatic (lim-fat′ik)

1. Pertaining to lymph. 2. A vascular channel that transports lymph. 3. Sometimes used to pertain to a sluggish or phlegmatic characteristic. SYN: vas lymphaticum. [L. lymphaticus, frenzied; Mod. L. use, of or for lymph]
afferent l. a l. vessel entering, or bringing lymph to, a node. SYN: afferent vessel (3) , vas lymphaticum afferens.
efferent l. SYN: vas efferens (1) .

lymphaticostomy
lymphaticostomy (lim-fat-i-kos′to-me)

Making an opening into a lymphatic duct. [lymphatic + G. stoma, mouth]

lymphatics
lymphatics (lim-fat′iks)

SYN: lymph vessels, under vessel.

lymphatitis
lymphatitis (lim-fa-ti′tis)

Obsolete term for inflammation of the lymphatic vessels or lymph nodes. [lymphatic + G. -itis, inflammation]

lymphatology
lymphatology (lim-fa-tol′o-je)

The study of the lymphatic system. [lymphatic + G. logos, study]

lymphatolysis
lymphatolysis (lim′fa-tol′i-sis)

Obsolete term for destruction of the lymphatic vessels or lymphoid tissue, or both. [lymphatic + G. lysis, dissolution]

lymphatolytic
lymphatolytic (lim′fa-to-lit′ik)

Pertaining to or characterized by lymphatolysis.

lymphectasia
lymphectasia (lim-fek-ta′ze-a)

SYN: lymphangiectasis. [lymph + G. ektasis, a stretching]

lymphedema
lymphedema (limf′e-de′ma)

Swelling (especially in subcutaneous tissues) as a result of obstruction of lymphatic vessels or lymph nodes and the accumulation of large amounts of lymph in the affected region. SEE ALSO: elephantiasis. [lymph + G. oidema, a swelling]
congenital l. hereditary l..
hereditary l. permanent pitting edema usually confined to the legs; two types, congenital (Milroy disease [MIM*153100], caused by mutation in the FMS-like tyrosine kinase 4 gene (FLT4) on 5q, or with onset at about the age of puberty (Meige disease [MIM*153200]); autosomal dominant inheritance.
l. praecox SYN: primary l..
primary l. a form of l. observed chiefly in young women and girls, characterized by diffuse swelling of the lower extremities. SYN: l. praecox.

lymphemia
lymphemia (lim-fe′me-a)

The presence of unusually large numbers of lymphocytes or their precursors, or both, in the circulating blood. [lymph(ocyte) + G. haima, blood]

lymphization
lymphization (lim-fi-za′shun)

The formation of lymph.

lymph node
lymph node [TA]

One of numerous round, oval, or bean-shaped bodies located along the course of lymphatic vessels, varying greatly in size (1–25 mm in diameter) and usually presenting a depressed area, the hilum, on one side through which blood vessels enter and efferent lymphatic vessels emerge. The structure consists of a fibrous capsule and internal trabeculae supporting lymphoid tissue and lymph sinuses; lymphoid tissue is arranged in nodules in the cortex and cords in the medulla of a node, with afferent vessels entering at many points of the periphery. SYN: nodus lymphoideus [TA] , lymphonodus&star, nodus lymphaticus&star, lymph gland, lymphaden, lymphoglandula.
abdominal lymph nodes [TA] the parietal and visceral lymph nodes of the abdomen, collectively. SYN: nodi lymphoidei abdominis [TA] .
lymph nodes of abdominal organs SYN: visceral lymph nodes of abdomen.
accessory lymph nodes [TA] the nodes of the lateral deep cervical group that are located along the accessory nerve; their efferent vessels pass to the supraclavicular lymph nodes. SYN: nodi lymphoidei accessorii [TA] , accessory nerve lymph nodes, companion lymph nodes of accessory nerve, nodi lymphatici comitantes nervi accessorii.
accessory nerve lymph nodes SYN: accessory lymph nodes.
anorectal lymph nodes SYN: pararectal lymph nodes.
anterior axillary lymph nodes pectoral axillary lymph nodes.
l. of anterior border of omental foramen [TA] one of the hepatic nodes located adjacent to the omental foramen. SYN: nodus lymphoideus foraminalis [TA] , foraminal l., foraminal node.
anterior cervical lymph nodes [TA] the group of lymph nodes located in the anterior region of the neck, divided into superficial and deep groups. SYN: nodi lymphoidei cervicales anteriores [TA] .
anterior deep cervical lymph nodes SYN: deep anterior cervical lymph nodes.
anterior jugular lymph nodes SYN: anterior superficial cervical lymph nodes.
anterior mediastinal lymph nodes SYN: brachiocephalic lymph nodes.
anterior superficial cervical lymph nodes [TA] the lymph nodes in the subcutaneous tissue of the anterior region of the neck. SYN: nodi lymphoidei cervicales anteriores superficiales [TA] , anterior jugular lymph nodes, nodi lymphoidei jugulares anteriores.
anterior tibial l. [TA] a small inconstant l. in front of the interosseous membrane along the upper part of the anterior tibial vessels. SYN: nodus tibialis anterior [TA] , anterior tibial node.
apical axillary lymph nodes [TA] the group of lymph nodes located at the apex of the axillary fossa that receive lymphatic drainage from other groups of axillary nodes and then drain in turn into the subclavian lymphatic trunk. SYN: nodi lymphoidei axillares apicales [TA] .
appendicular lymph nodes [TA] visceral nodes along the appendicular vessels in the mesoappendix; they receive afferent vessels from the vermiform appendix and send efferent vessels to the ileocolic lymph nodes. SYN: nodi lymphoidei appendiculares [TA] .
l. of arch of azygos vein [TA] a visceral l. of the right brachiocephalic group located adjacent to the arch of the azygos vein. SYN: nodus lymphoideus arcus venae azygos [TA] , l. of azygos arch, nodus lymphoideus arcus venae azygos.
lymph nodes around cardia of stomach [TA] a group of lymph nodes surrounding the cardia of the stomach. SYN: anulus lymphaticus cardiae [TA] , cardiac lymphatic ring, lymphatic ring of cardiac part of stomach.
axillary lymph nodes [TA] numerous nodes around the axillary veins that receive the lymphatic drainage from the upper limb, scapular region and pectoral region (including mammary gland); they drain into the subclavian trunk. SYN: nodi lymphoidei axillares [TA] , axillary glands.
l. of azygos arch SYN: l. of arch of azygos vein.
bifurcation lymph nodes SYN: inferior tracheobronchial lymph nodes.
brachial lymph nodes SYN: humeral axillary lymph nodes.
brachiocephalic lymph nodes located in the superior mediastinum in relation to the great vessels, these nodes receive lymph from the thymus, pericardium, and right side of the heart; their efferent vessels join those of the tracheal nodes to form the bronchomediastinal trunks. SYN: nodi lymphoidei brachiocephalici [TA] , anterior mediastinal lymph nodes, nodi lymphoidei mediastinales anteriores.
bronchopulmonary lymph nodes [TA] lymph nodes in the hilum of the lung that receive lymph from the pulmonary nodes, and drain to the tracheobronchial nodes. SYN: nodi lymphoidei bronchopulmonales [TA] , hilar lymph nodes.
buccal l. one of the chain of facial lymph nodes located superficial to the buccinator muscle. SYN: nodus lymphoideus buccinatorius [TA] , buccinator node, buccal node, nodus buccinatorius.
carinal lymph nodes SYN: inferior tracheobronchial lymph nodes.
celiac lymph nodes [TA] visceral nodes located along the celiac trunk that drain lymph from the stomach, duodenum, pancreas, spleen, and biliary tract and drain to the cisterna chyli via the right and left intestinal lymphatic trunks. SYN: nodi lymphoidei coeliaci [TA] .
central axillary lymph nodes [TA] nodes located around the midportion of the axillary vein; they receive afferent vessels from the humeral (lateral), pectoral (anterior), and subscapular (posterior) groups of axillary nodes and send efferent vessels to the apical group of axillary nodes; SYN: nodi lymphoidei axillares centrales [TA] .
central mesenteric lymph nodes SYN: central superior mesenteric lymph nodes. SEE ALSO: mesenteric lymph nodes.
central superior mesenteric lymph nodes [TA] the mesenteric lymph nodes located along the intestinal (jejunal and ileal) branches of the superior mesenteric artery. SYN: nodi lymphoidei superiores centrales [TA] , central mesenteric lymph nodes, middle group of mesenteric lymph nodes.
colic lymph nodes SYN: nodi lymphatici colici.left colic lymph nodes, middle colic lymph nodes, right colic lymph nodes.
common iliac lymph nodes [TA] parietal nodes located in association with the common iliac vein; they are subdivided into five groups: intermediate common iliac lymph nodes, between the common iliac artery and vein; lateral common iliac lymph nodes lateral to the vein; medial common iliac lymph nodes, medial to the vein; promontorial common iliac lymph nodes at the sacral promontory; and subaortic common iliac lymph nodes, at the bifurcation of the aorta; they all receive afferent vessels from the external and internal iliac nodes and send efferent vessels to the lumbar nodes. SYN: nodi lymphoidei iliaci communes [TA] .
companion lymph nodes of accessory nerve SYN: accessory lymph nodes.
cubital lymph nodes [TA] two groups of nodes, superficial and deep, lying along the basilic vein above the medial epicondyle; they receive afferents from the ulnar side of the forearm and hand, and send efferents to the brachial nodes. SYN: nodi lymphoidei cubitales [TA] , lymph nodes of elbow.
cystic l. [TA] a visceral l. at the neck of the gallbladder draining lymph into the hepatic nodes. SYN: nodus lymphoideus cysticus [TA] , cystic node.
deep anterior cervical lymph nodes [TA] the lymph nodes near the larynx, trachea, and thyroid gland. SYN: anterior deep cervical lymph nodes, nodi lymphoidei cervicales anteriores profundi.
deep inguinal lymph nodes [TA] several small inconstant nodes (proximal, intermediate, and distal) deep to the fascia lata and medial to the femoral vein; they receive lymph from the deep structures of the lower limb, from the glans penis and from superficial inguinal nodes; efferents pass to the external iliac nodes. SYN: nodi lymphoidei inguinales profundi.
deep lateral cervical lymph nodes [TA] the lymph nodes located in the posterior triangle of the neck deep to the investing layer of cervical fascia; they empty into the jugular trunk on the right or left side; the group is subdivided into four smaller chains: superior deep cervical nodes, inferior deep cervical nodes, accessory nodes, and supraclavicular nodes. SYN: nodi lymphoidei cervicales laterales profundi [TA] .
deep parotid lymph nodes [TA] the group of lymph nodes associated with the parotid gland lying deep to the parotid masseteric fascia. SYN: nodi lymphoidei parotidei profundi [TA] .
lymph nodes of elbow SYN: cubital lymph nodes.
external iliac lymph nodes [TA] parietal nodes located in association with the external iliac vein; they are subdivided into three groups: intermediate external iliac lymph nodes, between the vein and the external iliac artery; lateral external iliac lymph nodes, and medial external iliac lymph nodes, medial to the vein; they all receive afferent vessels from the inguinal nodes, lower abdominal wall, and pelvic viscera, and send efferent vessels to the common iliac nodes. SYN: nodi lymphoidei iliaci externi [TA] .
facial lymph nodes [TA] a chain of lymph nodes lying along the facial vein that receive afferent vessels from the eyelids, nose, cheek, lip, and gums, and send efferent vessels to the submandibular nodes. SYN: nodi lymphoidei faciales [TA] .
fibular l. a small inconstant l. located along the course of the fibular vein (venae comitantes). SYN: nodus lymphoideus fibularis [TA] , fibular node, peroneal l..
foraminal l. SYN: l. of anterior border of omental foramen.
gastroduodenal lymph nodes SYN: pyloric lymph nodes.
gluteal lymph nodes [TA] parietal nodes of the internal iliac nodes; they are subdivided into two groups: interior gluteal nodes, located along the inferior gluteal vein; superior gluteal nodes located along the superior gluteal vein. SYN: nodi lymphoidei gluteales [TA] .
lymph nodes of head and neck [TA] lymph nodes located in and draining the head and neck regions, ultimately draining via the jugular lymphatic trunks. SYN: nodi lymphoidei capitis et colli [TA] .
hepatic lymph nodes [TA] visceral nodes located along the hepatic artery as far as the porta hepatis; they drain the liver, gallbladder, stomach, duodenum, and pancreas, and send efferents to the celiac nodes. SYN: nodi lymphoidei hepatici [TA] .
hilar lymph nodes SYN: bronchopulmonary lymph nodes.
humeral axillary lymph nodes [TA] lymph nodes along the brachial vein that receive lymph drainage from most of the free upper limb and send efferent vessels to the central axillary lymph nodes. SYN: nodi lymphoidei axillares humerales [TA] , lateral axillary lymph nodes&star, nodi lymphoidei axillares laterales&star, brachial lymph nodes, nodi lymphoidei brachiales.
ileocolic lymph nodes [TA] visceral nodes located along the ileocolic artery that drain lymph from the ascending colon to the superior mesenteric nodes. SYN: nodi lymphoidei ileocolici [TA] .
inferior epigastric lymph nodes [TA] three or four parietal nodes placed along the inferior epigastric vessels; they receive afferents from the lower abdominal wall and empty into the external iliac nodes. SYN: nodi lymphoidei epigastrici inferiores [TA] .
inferior mesenteric lymph nodes [TA] visceral nodes located along the inferior mesenteric artery and its branches that drain the upper part of the rectum, the sigmoid colon, and descending colon. SYN: nodi lymphoidei mesenterici inferiores [TA] .
inferior phrenic lymph nodes [TA] small lymph nodes associated with the inferior phrenic vessels. SYN: nodi lymphoidei phrenici inferiores [TA] .
inferior tracheobronchial lymph nodes [TA] several large lymph nodes inferior to the tracheal bifurcation; they receive afferents from the bronchopulmonary nodes and the heart, and send efferents to the superior tracheobronchial and tracheal nodes. SYN: bifurcation lymph nodes, carinal lymph nodes, nodi lymphoidei tracheobronchiales inferiores.
infraauricular deep parotid lymph nodes [TA] small lymph nodes located deep to the parotid fascia and below the ear. SYN: infraauricular subfascial parotid lymph nodes, nodi lymphoidei parotidei profundi infra-auriculares.
infraauricular subfascial parotid lymph nodes SYN: infraauricular deep parotid lymph nodes.
intercostal lymph nodes [TA] one or two small nodes located posteriorly in each intercostal space; they receive lymph from the parietal pleura, intercostal space, and posterior body wall; the nodes in the upper spaces empty into the thoracic duct; the nodes in the lower spaces form a descending intercostal trunk that opens into the cisterna chyli. SYN: nodi lymphoidei intercostales [TA] .
interiliac lymph nodes [TA] several lymph nodes located between the external and internal iliac arteries and the obturator artery; these nodes are considered by some to be part of the medial external iliac nodes. SYN: nodi lymphoidei interiliaci [TA] .
intermediate lacunar l. [TA] an inconstant l. of the external iliac nodes frequently occurring between the external iliac artery and vein at the vascular space of the subinguinal compartment. SYN: nodus lymphoideus lacunaris intermedius [TA] , intermediate lacunar node.
intermediate lumbar lymph nodes [TA] the chain of lymph nodes located between the aorta and the inferior vena cava. SYN: nodi lymphoidei lumbales intermedii [TA] , lumbar lymph nodes.
internal iliac lymph nodes [TA] nodes that lie along the internal iliac artery and its branches; they receive lymph from the pelvic viscera, the gluteal region, and the deep parts of the perineum, and send efferent vessels to the common iliac nodes. SYN: nodi lymphoidei iliaci interni [TA] .
interpectoral lymph nodes [TA] small lymph nodes located between the pectoralis major and minor muscles; they receive lymph from the muscles and the mammary gland, and deliver lymph to the axillary lymphatic plexus. SYN: nodi lymphoidei interpectorales [TA] .
intraglandular deep parotid lymph nodes [TA] small lymph nodes of the deep parotid group lying within the parotid gland. SYN: nodi lymphoidei parotidei intraglandulares [TA] , intraglandular parotid lymph nodes.
intraglandular parotid lymph nodes SYN: intraglandular deep parotid lymph nodes.
intrapulmonary lymph nodes [TA] small nodes that occur along the bronchi within the parenchyma of the lung; they receive the drainage from localized areas of the lung and send efferents to bronchopulmonary nodes. SYN: nodi lymphoidei intrapulmonales [TA] , nodi lymphoidei pulmonales, pulmonary lymph nodes.
jugulodigastric l. [TA] a prominent l. in the deep lateral cervical group lying below the digastric muscle and anterior to the internal jugular vein; it receives lymphatic drainage from the pharynx, palatine tonsil, and tongue. SYN: nodus lymphoideus jugulodigastricus [TA] , jugulodigastric node, subdigastric node.
juguloomohyoid l. [TA] a l. of the lateral deep cervical group that lies above the intermediate tendon of the omohyoid muscle and anterior to the internal jugular vein; it receives lymphatic drainage from the submental, submandibular, and deep anterior cervical nodes; its efferent vessels go to other deep lateral cervical nodes. SYN: nodus lymphoideus juguloomohyoideus [TA] , juguloomohyoid node.
juxtaesophageal lymph nodes [TA] several nodes located along either side of the esophagus; they receive lymph from both the esophagus and the lungs. SYN: nodi lymphoidei juxtaesophageales [TA] , nodi lymphoidei juxtaesophageales pulmonales.
juxta-intestinal mesenteric lymph nodes [TA] the mesenteric lymph nodes located in immediate proximity to the jejunum or ileum. SYN: nodi lymphoidei juxtaintestinales [TA] .
lateral axillary lymph nodes humeral axillary lymph nodes.
lateral jugular lymph nodes deep nodes of the lateral cervical nodes lying lateral to the internal jugular vein; they usually empty into the jugular trunk. SYN: nodi lymphoidei jugulares laterales.
lateral lacunar l. [TA] a l. of the external iliac group located lateral to the external iliac artery at the vascular space of the subinguinal compartment. SYN: nodus lymphoideus lacunaris lateralis [TA] , lateral lacunar node.
lateral pericardial lymph nodes [TA] small lymph nodes located along the pericardiacophrenic vessels, they drain the pericardium. SYN: nodi lymphoidei pericardiales laterales [TA] .
left colic lymph nodes [TA] small nodes along the left colic artery and its branches that drain the left flexure and upper part of the descending colon; efferent vessels pass to the inferior mesenteric nodes. SYN: nodi lymphoidei colici sinistri [TA] .
left gastric lymph nodes [TA] nodes located along the left gastric artery and its branches; they are divided into paracardial, upper and lower groups. SYN: nodi lymphoidei gastrici sinistri [TA] , superior gastric lymph nodes.
left gastroepiploic lymph nodes SYN: left gastroomental lymph nodes.
left gastroomental lymph nodes [TA] nodes located in the greater omentum along the left gastroepiploic artery that drain part of the greater curvature of the stomach and greater omentum. SYN: nodi lymphoidei gastroomentales sinistri [TA] , left gastroepiploic lymph nodes.
left lumbar lymph nodes [TA] the chain of lymph nodes associated with the aorta in the abdomen; it is divided into three groups: lateral aortic lymph nodes on the left of the aorta; pre-aortic lymph nodes in front of the aorta; post-aortic lymph nodes, behind the aorta. SYN: nodi lymphoidei lumbales sinistri [TA] , lumbar lymph nodes.
l. of ligamentum arteriosum [TA] an inconstant l. of the anterior mediastinal group located adjacent to the ligamentum arteriosum. SYN: nodus lymphoideus ligamenti arteriosi [TA] , node of ligamentum arteriosum.
lingual lymph nodes [TA] l. along the lingual vein receiving drainage from the tongue (except tip); drain to submandibular lymph nodes. SYN: nodi lymphoidei linguales [TA] .
lymph nodes of lower limb [TA] the lymph nodes located in and draining the lower limb as a group; includes inguinal, popliteal, tibial, and fibular nodes. SYN: nodi lymphoidei membri inferioris [TA] .
lumbar lymph nodes SYN: right lumbar lymph nodes, intermediate lumbar lymph nodes, left lumbar lymph nodes.
malar l. [TA] one of the facial lymph nodes located near the zygomatic minor muscle. SYN: nodus lymphoideus malaris [TA] , malar node.
mandibular l. [TA] one of the facial lymph nodes located by the facial artery near the point it crosses the mandible. SYN: nodus lymphoideus mandibularis [TA] , mandibular nodes.
mastoid lymph nodes [TA] two or three nodes in the region of the mastoid process; they receive afferent lymphatic vessels from the scalp and auricle and send efferent vessels to the superior deep cervical nodes. SYN: nodi lymphoidei mastoidei [TA] , retroauricular lymph nodes.
medial lacunar l. [TA] a l. of the external iliac group located medial to the external iliac vein at the vascular space of the subinguinal compartment. SYN: nodus lymphoideus lacunaris medialis [TA] , medial lacunar node.
mesenteric lymph nodes [TA] nodes located in the mesentery; they are of three classes: ileocolic lymph nodes, juxtaintestinal mesenteric lymph nodes, and the central superior group of mesenteric lymph nodes. SYN: nodi lymphoidei mesenterici [TA] .
mesocolic lymph nodes [TA] nodes located in the mesocolon; they are of two classes: paracolic lymph nodes, located in immediate proximity to the colon; colic lymph nodes located along the arteries supplying the colon. SYN: nodi lymphoidei mesocolici [TA] , nodi lymphoidei paracolici.
middle colic lymph nodes [TA] nodes along the middle colic artery and its branches that drain the right colic flexure and most of the transverse colon. SYN: nodi lymphoidei colici medii [TA] .
middle group of mesenteric lymph nodes SYN: central superior mesenteric lymph nodes.
middle rectal l. a l. along the middle rectal artery that receives afferents from the pararectal nodes and sends efferents to the internal iliac nodes. SYN: middle rectal node, nodus lymphoideus rectalis medius.
nasolabial l. [TA] one of the facial lymph nodes located near the junction of the superior labial and facial arteries. SYN: nodus lymphoideus nasolabialis [TA] , nasolabial node.
obturator lymph nodes [TA] nodes of the internal iliac group located along the obturator artery. SYN: nodi lymphoidei obturatorii [TA] .
occipital lymph nodes [TA] one or two small nodes along the occipital vessels close to the trapezius muscle that receive afferents from the posterior scalp and drain into the superior deep lateral cervical nodes; these are the most posterior nodes of the pericervical collar of lymph nodes of the head and neck, which receive the drainage from the head. SYN: nodi lymphoidei occipitales [TA] .
pancreatic lymph nodes [TA] nodes draining the body and tail of the pancreas; they are subdivided into two groups: inferior pancreatic lymph nodes [TA] (nodi lymphoidei pancreatici inferiores [TA]), located along the inferior pancreatic artery; superior pancreatic lymph nodes [TA] (nodi lymphoidei pancreatici superiores [TA]), located along the splenic artery near the origin of its pancreatic branches. SYN: nodi lymphoidei pancreatici [TA] .
pancreaticoduodenal lymph nodes [TA] nodes along the superior and inferior pancreaticoduodenal arteries. SYN: nodi lymphoidei pancreaticoduodenales [TA] .
pancreaticosplenic lymph nodes lymph nodes of the pancreatic tail and spleen, receiving afferents from both organs plus the greater curvature of the stomach; they drain to the celiac lymph nodes. SYN: nodi lymphoidei pancreaticosplenales [TA] , nodi lymphoidei pancreaticolienales.
paramammary lymph nodes [TA] several lymph nodes on the lateral side of the mammary gland that receive afferents from the mammary gland and send efferents to the axillary pectoral group of lymph nodes. The paramammary lymph nodes are commonly considered as part of the pectoral axillary nodes. SYN: nodi lymphoidei paramammarii [TA] .
pararectal lymph nodes [TA] nodes located on either side of the rectum; they send efferents to the middle and superior rectal nodes. SYN: nodi lymphoidei pararectales [TA] , anorectal lymph nodes, nodi lymphoidei anorectales.
parasternal lymph nodes [TA] a number of small nodes that lie along the course of the internal thoracic vessels; lymph enters these nodes from the anterior intercostal spaces, pericardium, diaphragm, liver and medial mammary gland; the efferent vessels pass upward to join the bronchomediastinal trunk of the same side. SYN: nodi lymphoidei parasternales [TA] .
paratracheal l. [TA] nodes along the sides of the trachea in the neck and in the posterior mediastinum; receive drainage of superior (and inferior) tracheobranchial nodes, trachea, and esophagus; drain to bronchomediastinal lymphatic trunk(s), thoracic duct. SYN: nodi lymphoidei paratracheales [TA] , tracheal lymph nodes.
parauterine lymph nodes [TA] nodes on either side of the uterus draining lymph to the internal iliac nodes and to the lumbar nodes via lymphatic vessels following the ovarian arteries. SYN: nodi lymphoidei parauterini [TA] .
paravaginal lymph nodes [TA] lymph nodes in association with the vagina; they drain to the internal iliac nodes. SYN: nodi lymphoidei paravaginales [TA] .
paravesical lymph nodes the lymph nodes located around the urinary bladder and, in the male, the prostate; there are three groups: prevesicular lymph nodes, in front of the bladder; lateral vesical lymph nodes, on the right and left sides; postvesicular lymph nodes behind the bladder.
parietal lymph nodes [TA] the lymph nodes draining the walls of the abdomen or of the pelvis (as opposed to the visceral nodes draining the abdominopelvic viscera). SYN: nodi lymphoidei parietales [TA] , parietal nodes.
pectoral axillary lymph nodes [TA] lymph nodes located along the lateral thoracic vein; they receive the drainage of the pectoral region, including most of the drainage of the breast. SYN: nodi lymphoidei axillares pectorales [TA] , anterior axillary lymph nodes&star, nodi lymphoidei axillares anteriores.
pelvic lymph nodes [TA] the parietal and visceral lymph nodes of the pelvis, collectively. SYN: nodi lymphoidei pelvis [TA] .
peroneal l. SYN: fibular l..
popliteal lymph nodes [TA] two groups of nodes located in the popliteal fossa: the superficial popliteal lymph nodes, located around the termination of the small saphenous vein, that drain the skin of the back of the leg and lateral side of the foot; and the deep popliteal lymph nodes, located around the popliteal vessels, that drain the superficial group, the deep structures of the leg, and the knee joint. SYN: nodi lymphoidei popliteales [TA] .
posterior axillary lymph nodes subscapular axillary lymph nodes.
posterior mediastinal lymph nodes SYN: prevertebral lymph nodes.
posterior tibial l. [TA] a small inconstant l. located along the course of the posterior tibial artery. SYN: nodus lymphoideus tibialis posterior [TA] , posterior tibial node.
preauricular deep parotid lymph nodes [TA] small lymph nodes located deep to the parotid fascia and in front of the ear. SYN: nodi lymphoidei parotidei profundi preauriculares [TA] .
prececal lymph nodes [TA] nodes located in front of the cecum draining lymph to the ileocolic nodes. SYN: nodi lymphoidei precaecales [TA] .
prelaryngeal lymph nodes [TA] lymph nodes of the deep anterior cervical group that lie in front of the larynx; they drain into the lateral deep lateral cervical nodes. SYN: nodi lymphoidei prelaryngeales [TA] .
prepericardial lymph nodes [TA] several small lymph nodes located between the pericardium and the sternum, in the anterior mediastinum. SYN: nodi lymphoidei prepericardiaci [TA] .
pretracheal lymph nodes [TA] lymph nodes of the deep anterior cervical group that lie in front of the trachea; they drain into the deep lateral cervical group or into the parasternal nodes. SYN: nodi lymphoidei pretracheales [TA] .
prevertebral lymph nodes [TA] nodes located along the thoracic aorta; they receive vessels from the esophagus, diaphragm, liver, and pericardium and send efferents to the thoracic duct and bronchomediastinal lymphatic trunk(s). SYN: nodi lymphoidei prevertebrales&star, nodi lymphoidei mediastinales posteriores, posterior mediastinal lymph nodes.
proximal deep inguinal l. [TA] one of the deep inguinal lymph nodes located in or adjacent to the femoral canal; sometimes mistaken for a femoral hernia when enlarged. SYN: nodus lymphoideus proximalis profundus [TA] , node of Cloquet, Rosenmüller gland, Rosenmüller node.
pulmonary lymph nodes SYN: intrapulmonary lymph nodes.
pyloric lymph nodes [TA] group of lymph nodes surrounding the pylorus, draining lymph into the right gastric or the right gastro-omental lymph nodes; it is divided into three smaller groups: suprapyloric nodes, superior to the pylorus; subpyloric nodes, inferior to the pylorus; and retropyloric nodes, posterior to the pylorus. SYN: gastroduodenal lymph nodes, nodi lymphoidei pylorici.
retroauricular lymph nodes SYN: mastoid lymph nodes.
retrocecal lymph nodes [TA] nodes located behind the cecum draining lymph into the ileocolic nodes. SYN: nodi lymphoidei retrocecales [TA] .
retropharyngeal lymph nodes [TA] the three groups of lymph nodes, one median and two lateral, located between the pharynx and the prevertebral layer of cervical fascia; they receive lymph from the nasopharynx, the auditory tube, and the atlanto-occipital and atlantoaxial joints. SYN: nodi lymphoidei retropharyngeales [TA] .
retropyloric lymph nodes [TA] a group of lymph nodes located behind the pylorus. SYN: nodi lymphoidei retropylorici [TA] , retropyloric nodes.
right colic lymph nodes [TA] nodes located along the right colic artery that drain the upper part of the ascending colon. SYN: nodi lymphoidei colici dextri [TA] .
right gastric lymph nodes [TA] small nodes along the course of the right gastric artery that drain part of the lesser curvature of the stomach. SYN: nodi lymphoidei gastrici dextri [TA] .
right gastroepiploic lymph nodes SYN: right gastroomental lymph nodes.
right gastroomental lymph nodes [TA] nodes located in the greater omentum along the right gastroepiploic artery that drain part of the greater curvature of the stomach and the greater omentum. SYN: nodi lymphoidei gastroomentales dextri [TA] , right gastroepiploic lymph nodes.
right lumbar lymph nodes [TA] the chain of nodes associated with the inferior vena cava; it is divided into three groups: lateral caval nodes, on the right of the inferior vena cava; precaval nodes, anterior to the inferior vena cava; postcaval nodes, posterior to the inferior vena cava. SYN: nodi lymphoidei lumbales dextri [TA] , lumbar lymph nodes.
sacral lymph nodes [TA] nodes in the concavity of the sacrum that drain the rectum and posterior pelvic wall. SYN: nodi lymphoidei sacrales [TA] .
sentinel l. the first l. to receive lymphatic drainage from a malignant tumor; the sentinel node is identified as the first to take up a radionuclide or dye injected into the tumor; increasingly used in operations for melanoma and breast cancer; if the sentinel node is free of metastasis, more distal nodes are also free. SEE ALSO: signal l.. SYN: sentinel node.
sigmoid lymph nodes [TA] nodes of the inferior mesenteric group, located along the sigmoid arteries. SYN: nodi lymphoidei sigmoidei [TA] .
signal l. a firm supraclavicular l., especially on the left side, sufficiently enlarged that it is palpable from the cutaneous surface; such a l. is so termed because it may be the first recognized presumptive evidence of a malignant neoplasm in one of the viscera. A signal l. that is known to contain a metastasis from a malignant neoplasm is sometimes designated by an old eponym, Troisier ganglion. SEE ALSO: sentinel l.. SYN: jugular gland, Virchow node.
splenic lymph nodes [TA] nodes near the hilum of the spleen; they receive afferents from the spleen and stomach, and send efferents to the pancreatic-postsplenic and celiac nodes. SYN: nodi lymphoidei splenici [TA] , nodi lymphoidei lienales&star.
subaortic lymph nodes [TA] nodes of the common iliac group located at the bifurcation of the aorta. SYN: nodi lymphoidei subaortici [TA] .
submandibular lymph nodes [TA] four or five nodes that lie in relationship to the mandible and the submandibular gland; they receive vessels from the face below the eye and from the tongue and drain into the superior deep cervical nodes, particularly the jugulodigastric node; these nodes are part of the pericervical collar of lymph nodes that initially receive drainage from the head. SYN: nodi lymphoidei submandibulares [TA] .
submental lymph nodes [TA] small nodes that lie superficial to the mylohyoid muscle; they receive afferents from the lower lip, chin, and the tip of the tongue, and send efferents to the deep lateral cervical nodes; these nodes are part of the pericervical collar of lymph nodes that initially receives drainage from the head. SYN: nodi lymphoidei submentales [TA] .
subpyloric lymph nodes [TA] a group of pyloric nodes located below the pylorus. SYN: nodi lymphoidei subpylorici [TA] , subpyloric node.
subscapular axillary lymph nodes [TA] nodes of the axillary region located along the subscapular vein and its tributaries; they receive afferent vessels from the dorsal surface of the thorax and scapular region and send efferent vessels to the central group of lymph nodes. SYN: nodi lymphoidei axillares subscapulares [TA] , nodi lymphoidei axillares posteriores&star, posterior axillary lymph nodes&star.
superficial inguinal lymph nodes [TA] a group of 12–20 nodes that lie in the subcutaneous tissue below the inguinal ligament and along the terminal part of the great saphenous vein; they drain the skin and subcutaneous tissue of the lower abdominal wall, perineum, buttock, external genitalia, and lower limb; they are subdivided into three groups: inferior (vertical) group of superficial inguinal lymph nodes, located inferior to the saphenous opening, receiving drainage of the lower limb; superolateral (lateral horizontal) superficial inguinal lymph nodes located lateral to the saphenous opening, receiving drainage of lateral buttock and lower anterior abdominal wall; and superomedial (medial horizontal) superficial inguinal lymph nodes, located medial to the saphenous opening, receiving drainage of the perineum and external genitalia. SYN: nodi lymphoidei inguinales superficiales [TA] .
superficial lateral cervical lymph nodes [TA] 1–4 nodes lying along the external jugular vein; they drain the skin and superficial structures over the region of the sternocleidomastoid muscle and send efferent vessels to the deep lateral cervical lymph nodes. SYN: nodi lymphoidei cervicales laterales superficiales [TA] .
superficial parotid lymph nodes [TA] several small lymph nodes located in the subcutaneous tissue in the parotid region. SYN: nodi lymphoidei parotidei superficiales [TA] .
superior gastric lymph nodes SYN: left gastric lymph nodes.
superior mesenteric lymph nodes [TA] the numerous nodes located in the mesentery along the superior mesenteric artery; they receive lymph from the central mesenteric lymph nodes and drain into the intestinal lymph trunk. SYN: nodi lymphoidei mesenterici superiores [TA] , nodi lymphoidei centrales.
superior phrenic lymph nodes [TA] three groups of small nodes, anterior, middle, and posterior, on the upper surface of the diaphragm; they receive afferents from the liver, diaphragm, and intercostal spaces and send efferents to parasternal and posterior mediastinal nodes. SYN: nodi lymphoidei phrenici superiores [TA] .
superior rectal lymph nodes [TA] nodes of the inferior mesenteric group, located along the superior rectal artery. SYN: nodi lymphoidei rectales superiores [TA] .
superior tracheobronchial lymph nodes [TA] several large lymph nodes of the posterior mediastinum located superior to the bronchi at their union with the trachea; receives lymph from inferior tracheobronchial lymph nodes and bronchopulmonary nodes; drain to paratracheal nodes. SYN: nodi lymphoidei tracheobronchiales superiores [TA] .
supraclavicular lymph nodes [TA] the portion of the inferior deep lateral cervical nodes located between the inferior belly of the omohyoid muscle and the clavicle; afferent vessels come from adjacent regions including the mediastinum; efferent vessels terminate in the subclavian trunk. SYN: nodi lymphoidei supraclaviculares [TA] .
suprapyloric l. [TA] a l. located above the pylorus. SYN: nodus lymphoideus suprapyloricus [TA] , suprapyloric node.
thoracic lymph nodes [TA] the parietal and visceral lymph nodes of the thorax, collectively. SYN: nodi lymphoidei thoracis [TA] .
thyroid lymph nodes [TA] nodes of the deep anterior cervical group located around the thyroid gland; they drain into the deep lateral cervical group. SYN: nodi lymphoidei thyroidei [TA] .
tracheal lymph nodes SYN: paratracheal l..
lymph nodes of upper limb [TA] lymph nodes located in and draining the upper limb, ultimately drained by the subclavian lymphatic trunk; included are the axillary, interpectoral, deltopectoral (infraclavicular), brachial, and cubital nodes. SYN: nodi lymphoidei membri superioris [TA] .
visceral lymph nodes [TA] the lymph nodes draining the viscera of the abdomen or of the pelvis as opposed to the parietal nodes draining the body walls. SYN: nodi lymphoidei viscerales [TA] , visceral nodes.
visceral lymph nodes of abdomen [TA] the numerous lymph nodes receiving lymph from abdominal organs located in association with the visceral branches of the aorta. SYN: nodi lymphoidei abdominis viscerales [TA] , lymph nodes of abdominal organs.

lympho- lympho-, lymph-

Lymph. [L. lympha, spring water]

lymphoblast
lymphoblast (lim′fo-blast)

A young immature cell that matures into a lymphocyte and is characterized by more abundant cytoplasm than in a lymphocyte, a nucleus in which the chromatin is finer than in a lymphocyte (but coarser than in a myeloblast), and one or two rather prominent nucleoli. SYN: lymphocytoblast. [lympho- + G. blastos, germ]

lymphoblastic
lymphoblastic (lim-fo-blas′tik)

Pertaining to the production of lymphocytes.

lymphoblastoma
lymphoblastoma (lim-fo-blas-to′ma)

SYN: lymphoblastic lymphoma. [lymphoblast + G. -oma, tumor]
giant follicular l. SYN: nodular lymphoma.

lymphoblastosis
lymphoblastosis (lim′fo-blas-to′sis)

The presence of lymphoblasts in the peripheral blood; sometimes used as a synonym for acute lymphocytic leukemia. [lymphoblast + G. -osis, condition]

lymphocele
lymphocele (lim′fo-sel)

A cystic mass that contains lymph, usually from diseased or injured lymphatic channels. SYN: lymphocyst. [lympho- + G. kele, tumor]

lymphocerastism
lymphocerastism (lim-fo-ser′as-tizm)

Obsolete term for the process of formation of cells in the lymphocytic series. [lympho- + G. kerastos, mixed, mingled]

lymphocinesis
lymphocinesis, lymphocinesia (lim′fo-si-ne′sis, ne-ze-a)

SYN: lymphokinesis.

lymphocyst
lymphocyst (lim′fo-sist)

SYN: lymphocele. [lympho- + G. kystis, bladder]

lymphocytapheresis
lymphocytapheresis (lim′fo-sit-af-e-re′sis)

Separation and removal of lymphocytes from the withdrawn blood, with the remainder of the blood retransfused into the donor. SYN: lymphapheresis. [lymphocyte + G. aphairesis, a withdrawal]

lymphocyte
lymphocyte (lim′fo-sit)

A white blood cell formed in lymphatic tissue throughout the body ( e.g., lymph nodes, spleen, thymus, tonsils, Peyer patches, and sometimes in bone marrow) and in normal adults making up approximately 22–28% of the total number of leukocytes in the circulating blood. Lymphocytes are generally small (7–8 μm), but larger forms are frequent (10–20 μm); with Wright (or a similar) stain, the nucleus is deeply colored (purple-blue), and is composed of dense aggregates of chromatin within a sharply defined nuclear membrane; the nucleus is usually round, but may be slightly indented, and is eccentrically situated within a relatively small amount of light blue cytoplasm that ordinarily contains no granules; especially in larger forms, the cytoplasm may be fairly abundant and include several bright red-violet fine granules; in contrast to granules of the myeloid series of cells, those in lymphocytes do not yield a positive oxidase or peroxidase reaction. Lymphocytes are divided into 2 principal groups, termed T and B cells, based on their surface molecules as well as function. Natural killer cells, which are large granular lymphocytes, represent a small percentage of the l. population. SYN: lymph cell, lympholeukocyte. [lympho- + G. kytos, call]
B l. an immunologically important l. that is not thymus-dependent, is of short life, and resembles the bursa-derived l. of birds in that it is responsible for the production of immunoglobulins, i.e., it is the precursor of the plasma cell and expresses immunoglobulins on its surface but does not release them. It does not play a direct role in cell-mediated immunity. SEE ALSO: T l.. SYN: B cell (2) .
pre-B l. an early B-lymphoid type cell that is recognized by immunofluorescence as a μ-positive, L-chain-negative bone marrow cell.
Rieder l. an abnormal form of l. that has a greatly indented (or lobed), slightly twisted nucleus; such cells are usually observed in certain examples of chronic lymphocytic leukemia.
T l. a thymocyte-derived l. of immunologic importance that is long-lived (months to years) and is responsible for cell-mediated immunity. T lymphocytes form rosettes with sheep erythrocytes and, in the presence of transforming agents (mitogens), differentiate and divide. These cells have characteristic CD3 surface markers and may be further divided into subsets according to function, such as helper, cytotoxic, etc. SEE ALSO: B l.. SYN: T cell.
transformed l. l. transformation.
tumor-infiltrating lymphocytes (TIL, TILS) (lim′fo-sitz) lymphocytes collected from the site of a tumor and exposed to IL-2 in vitro to expand the population. When these cells are injected back into the tumor-bearing host, they will specifically kill the tumor from which they originated.

lymphocythemia
lymphocythemia (lim′fo-si-the′me-a)

SYN: lymphocytosis.

lymphocytic
lymphocytic (lim-fo-sit′ik)

Pertaining to or characterized by lymphocytes.

lymphocytoblast
lymphocytoblast (lim-fo-si′to-blast)

SYN: lymphoblast. [lymphocyte + G. blastos, germ]

lymphocytoma
lymphocytoma (lim′fo-si-to′ma)

A circumscribed nodule or mass of mature lymphocytes, grossly resembling a neoplasm. [lymphocyte + G. -oma, tumor]
benign l. cutis a soft red to violaceous skin nodule often involving the head, caused by dense infiltration of the dermis by lymphocytes and histiocytes, often forming lymphoid follicles, separated from the epidermis by a narrow noninfiltrating layer. SYN: cutaneous pseudolymphoma, Spiegler-Fendt sarcoid.

lymphocytopenia
lymphocytopenia (lim′fo-si-to-pe′ne-a)

SYN: lymphopenia.

lymphocytopoiesis
lymphocytopoiesis (lim′fo-si-to-poy-e′sis)

The formation of lymphocytes. [lymphocyte + G. poiesis, a making]

lymphocytosis
lymphocytosis (lim′fo-si-to′sis)

A form of actual or relative leukocytosis in which there is an increase in the number of lymphocytes. SYN: lymphocythemia, lymphocytic leukocytosis.

lymphoderma
lymphoderma (lim′fo-der′ma)

A condition resulting from any disease of the cutaneous lymphatic vessels. [lympho- + G. derma, skin]

lymphoduct
lymphoduct (lim′fo-dukt)

A lymphatic vessel. See lymph vessels, under vessel. [lympho- + L. ductus, a leading]

lymphogenesis
lymphogenesis (lim-fo-gen′e-sis)

Lymph production. [lympho- + G. genesis, production]

lymphogenic
lymphogenic (lim-fo-jen′ik)

SYN: lymphogenous (1) .

lymphogenous
lymphogenous (lim-foj′e-nus)

1. Originating from lymph or the lymphatic system. SYN: lymphogenic. 2. Producing lymph.

lymphoglandula
lymphoglandula (lim-fo-glan′doo-la)

SYN: lymph node.

lymphogranuloma
lymphogranuloma (lim′fo-gran-u-lo′ma)

Old nonspecific term used with reference to a few basically dissimilar diseases in which the pathologic processes result in granulomas or granulomalike lesions, especially in various groups of lymph nodes (which then become conspicuously enlarged).
l. benignum old term for sarcoidosis.
l. inguinale SYN: venereal l..
l. malignum old term for Hodgkin disease.
Schaumann l. old eponym for sarcoidosis.
venereal l., l. venereum a venereal infection usually caused by Chlamydia trachomatis, and characterized by a transient genital ulcer and inguinal adenopathy in the male; in the female, perirectal lymph nodes are involved and rectal stricture is a common occurrence. SYN: Favre-Durand-Nicholas disease, l. inguinale, Nicolas-Favre disease, tropical bubo.

lymphogranulomatosis
lymphogranulomatosis (lim-fo-gran′u-lo-ma-to′sis)

Any condition characterized by the occurrence of multiple and widely distributed lymphogranulomas.

lymphography
lymphography (lim-fog′ra-fe)

Visualization of lymphatics (lymphangiography) and lymph nodes (lymphadenography) by radiography following the intralymphatic injection of a contrast medium, usually an iodized oil. [lympho- + grapho, to write]

lymphohistiocytosis
lymphohistiocytosis (lim′fo-his′te-o-si-to′sis)

Proliferation or infiltration of lymphocytes and histiocytes.
familial erythrophagocytic l. (FEL) SYN: familial hemophagocytic l..
familial hemophagocytic l. (FMLH) an extremely rare, usually fatal disease of childhood characterized by multiorgan infiltration with activated macrophages and lymphocytes. The disease is often familial and appears to be inherited as an autosomal recessive trait. SYN: familial erythrophagocytic l..

lymphoid
lymphoid (lim′foyd)

Resembling lymph or lymphatic tissue, or pertaining to the lymphatic system. [lympho- + G. eidos, appearance]

lymphoidectomy
lymphoidectomy (lim-foy-dek′to-me)

Excision of lymphoid tissue. [lymphoid + G. ektome, excision]

lymphoidocyte
lymphoidocyte (lim-foy′do-sit)

A primitive mesenchymal cell believed to be capable of differentiating into all types of lymphoid cells, including lymphocytes, littoral cells, and reticular cells of lymph nodes.

lymphokine
lymphokine (lim′fo-kinz)

Hormonelike peptide, released by activated lymphocytes, that mediates immune response; a cytokine obtained from lymphocytes. [lymphocyte + G. kineo, to set in motion]

lymphokinesis
lymphokinesis (lim′fo-ki-ne′sis)

1. Circulation of lymph in the lymphatic vessels and through the lymph nodes. 2. Movement of endolymph in the semicircular canals of the inner ear. SYN: lymphocinesis, lymphocinesia. [lympho- + G. kinesis, movement]

lympholeukocyte
lympholeukocyte (lim′fo-loo′ko-sit)

SYN: lymphocyte.

lymphology
lymphology (lim-fol′o-je)

SYN: lymphangiology. [lympho- + G. logos, study]

lymphoma
lymphoma (lim-fo′ma)

Any neoplasm of lymphoid tissue; in general use, synonymous with malignant l.. [lympho- + G. -oma, tumor]
adult T-cell l. (ATL) an acute or subacute disease associated with a human T-cell virus, with lymphadenopathy, hepatosplenomegaly, skin lesions, peripheral blood involvement, and hypercalcemia. SYN: adult T-cell leukemia.
anaplastic large cell l. a form of l. characterized by anaplasia of cells, sinusoidal growth, and immunoreactivity with CD30 (Ki-1 or Ber-H2). SYN: Ki-1+ l..
benign l. of the rectum obsolete term for a rectal polyp composed of lymphoid tissue with follicle formation, covered by mucosa.
Burkitt l. a form of malignant l. reported in African children, frequently involving the jaw and abdominal lymph nodes. Geographic distribution of Burkitt l. suggests that it is found in areas with endemic malaria. It is primarily a B-cell neoplasm and is believed to be caused by Epstein-Barr virus, a member of the family Herpesviridae, which can be isolated from tumor cells in culture; occasional cases of l. with similar features have been reported in the United States.
chronic lymphocytic l. a type of low-grade non-Hodgkin l. characterized by lymphocytosis, lymphadenoathy, and, in late stages, hepatosplenomegaly; may evolve into chronic lymphocytic leukemia over the course of several years.
diffuse small cleaved cell l. diffuse poorly differentiated lymphocytic l.; follicular center cell l. that lacks a follicular pattern; malignancy is of intermediate grade.
extranodal marginal zone l. SYN: MALToma.
follicular l. SYN: nodular l..
follicular predominantly large cell l. a B-cell l. of intermediate malignancy.
follicular predominantly small cleaved cell l. SYN: poorly differentiated lymphocytic l..
histiocytic l. a malignant tumor of reticular tissue composed predominantly of neoplastic histiocytes. SEE ALSO: large cell l..
Hodgkin l. SYN: Hodgkin disease.
immunoblastic l. a monomorphous proliferation of immunoblasts involving the lymph nodes; it may develop in some patients with angioimmunoblastic lymphadenopathy.
Ki-1+ l. SYN: anaplastic large cell l..
large cell l. l. composed of large mononuclear cells of undetermined type. Many lymphomas formerly classified as histiocytic have in recent years been shown to consist of large lymphocytes.
Lennert l. malignant l. with a high proportion of diffusely scattered epithelioid cells, tonsillar involvement, and an unpredictable course.
lymphoblastic l. a diffuse l. in children, with supradiaphragmatic distribution and T lymphocytes having convoluted nuclei; many patients develop acute lymphoblastic leukemia. SYN: lymphoblastoma.
malignant l. general term for ordinarily malignant neoplasms of lymphoid and reticuloendothelial tissues which present as apparently circumscribed solid tumors composed of cells that appear primitive or resemble lymphocytes, plasma cells, or histiocytes. Lymphomas appear most frequently in lymph nodes, spleen, or other normal sites of lymphoreticular cells; when disseminated, Lymphomas, especially of the lymphocytic type, may invade the peripheral blood and manifest as leukemia. Lymphomas are classified by cell type, degrees of differentiation, and nodular or diffuse pattern; Hodgkin disease and Burkitt l. are special forms.
mantle cell l. a clinically and biologically distinct B-cell neoplasm with a recurring acquired genetic abnormality, the t(11;14) translocation, and a heterogeneous histologic appearance that may lead to confusion with reactive or other neoplastic lymphoproliferative disorders.
marginal zone l. a heterogeneous group of neoplasms originating from the B-cell–rich zones of the lymph nodes, spleen, or extranodal lymphoid tissue. Those tumors originating from mucosa-associated lymphoid tissue (MALT), most often in the stomach, intestines, salivary glands, and lungs, are called MALTomas.
Mediterranean l. SYN: immunoproliferative small intestinal disease.
nodular l. malignant l. arising from lymphoid follicular B cells which may be small or large, growing in a nodular pattern. SYN: follicular l., giant follicular lymphoblastoma.
nodular histiocytic l. SYN: poorly differentiated lymphocytic l..
non-Hodgkin l. (NHL) a l. other than Hodgkin disease, classified by Rappaport into a nodular or diffuse tumor pattern and by cell type; a working or international formulation separates such lymphomas into low, intermediate, and high grade malignancy and into cytologic subtypes reflecting follicular center cell or other origin.
peripheral T-cell l., unspecified a heterogeneous group of T-cell neoplasms expressing typical T-cell markers such as CD2, CD3, CD5, and either T-cell α/β or γ/δ receptors.
poorly differentiated lymphocytic l. a B-cell l. with nodular or diffuse lymph node or bone marrow involvement by large lymphoid cells. SYN: follicular predominantly small cleaved cell l., nodular histiocytic l..
small lymphocytic l. SYN: well-differentiated lymphocytic l..
T-cell–rich, B-cell l. a B-cell l. in which more than 90% of the cells are of T-cell origin, masking the large cells that form the neoplastic B-cell component. SEE ALSO: adult T-cell l..
well-differentiated lymphocytic l. essentially the same disease as chronic lymphocytic leukemia, except that lymphocytes are not increased in the peripheral blood; lymph nodes are enlarged and other lymphoid tissue or bone marrow is infiltrated by small lymphocytes. SYN: small lymphocytic l..

lymphomatoid
lymphomatoid (lim-fo′ma-toyd)

Resembling a lymphoma.

lymphomatosis
lymphomatosis (lim′fo-ma-to′sis)

Any condition characterized by the occurrence of multiple, widely distributed sites of involvement with lymphoma.

lymphomatous
lymphomatous (lim-fo′ma-tus)

Pertaining to or characterized by lymphoma.

lymphonodus
lymphonodus

lymph node.

lymphopathia
lymphopathia (lim-fo-path′e-a)

SYN: lymphopathy.

lymphopathy
lymphopathy (lim-fop′a-the)

Any disease of the lymphatic vessels or lymph nodes. SYN: lymphopathia. [lympho- + G. pathos, suffering]

lymphopenia
lymphopenia (lim-fo-pe′ne-a)

A reduction, relative or absolute, in the number of lymphocytes in the circulating blood. SYN: lymphocytic leukopenia, lymphocytopenia. [lympho- + G. penia, poverty]

lymphoplasmapheresis
lymphoplasmapheresis (lim′fo-plaz′ma-fe-re′sis)

Separation and removal of lymphocytes and plasma from the withdrawn blood, with the remainder of the blood retransfused into the donor. [lymphocyte + plasma + G. aphairesis, a withdrawal]

lymphopoiesis
lymphopoiesis (lim-fo-poy-e′sis)

The formation of lymphatic tissue. [lympho- + G. poiesis, a making]

lymphopoietic
lymphopoietic (lim-fo-poy-et′ik)

Pertaining to or characterized by lymphopoiesis.

lymphoreticulosis
lymphoreticulosis (lim′fo-re-tik-u-lo′sis)

Proliferation of the reticuloendothelial cells (macrophages) of the lymph nodes.
benign inoculation l. SYN: catscratch disease.

lymphorrhagia
lymphorrhagia (lim-fo-ra′je-a)

SYN: lymphorrhea. [lympho- + G. rhegnymi, to burst forth]

lymphorrhea
lymphorrhea (lim-fo-re′a)

An escape of lymph onto the surface of the skin from ruptured, torn, or cut lymphatic vessels. SYN: lymphorrhagia. [lympho- + G. rhoia, a flow]

lymphorrhoid
lymphorrhoid (lim′fo-royd)

A dilation of a lymph channel, resembling a hemorrhoid. [lymph + -rrhoid, tending to leak, on the analogy of hemorrhoid]

lymphoscintigraphy
lymphoscintigraphy (lim′fo-sin-tig′ra-fe)

Scintillation scanning of lymphatics or lymph nodes following intralymphatic or subcutaneous injection of a radionuclide.

lymphosis
lymphosis (lim-fo′sis)

Obsolete term for lymphocytic leukemia.

lymphostasis
lymphostasis (lim-fos′ta-sis)

Obstruction of the normal flow of lymph. [lympho- + G. stasis, a standing still]

lymphotaxis
lymphotaxis (lim-fo-tak′sis)

The exertion of an effect that attracts or repels lymphocytes. [lympho- + G. taxis, orderly arrangement]

lymphotoxicity
lymphotoxicity (lim′fo-tok-sis′i-te)

Toxicity to lymphocytes.

lymphotoxin
lymphotoxin (lim′fo-tok-sin)

A lymphokine from T lymphocytes that lyses or damages many cell types.

lymphotrophy
lymphotrophy (lim-fot′ro-fe)

Nourishment of the tissues by lymph in parts devoid of blood vessels. [lympho- + G. trophe, nourishment]

lymphuria
lymphuria (lim-foo′re-a)

Discharge of lymph in the urine. [lympho- + G. ouron, urine]

Lynch
Lynch

Henry T., 20th century U.S. oncologist. See L. syndrome.

lynestrenol
lynestrenol (lin-es′tren-ol)

A progestational agent, used with mestranol as an oral contraceptive. SYN: ethinylestrenol.

lyo- lyo-

Dissolution. SEE ALSO: lyso-. [G. lyo, to loosen, dissolve]

lyoenzyme
lyoenzyme (li-o-en′zim)

1. Any enzyme existing in the cell in soluble form. 2. A soluble enzyme.

lyolysis
lyolysis (li-ol′i-sis)

Rarely used term for solvolysis.

Lyon
Lyon

B. B. Vincent, U.S. physician, 1880–1953. See Meltzer-L. test.

Lyon
Lyon

Mary F., English cytogeneticist, *1925. See L. hypothesis, lyonization.

lyonization
lyonization (li′on-i-za′shun)

The normal phenomenon that wherever there are two or more haploid sets of X-linked genes in each cell all but one of the genes are inactivated apparently at random and have no phenotypic expression. L. is usual but not invariable for all loci. Its randomness explains the more variable espressivity of X-linked traits in women than in men. L. occurs in men with the Klinefelter (XXY) karyotype. SEE ALSO: gene dosage compensation. SYN: Lyon hypothesis, X-inactivation. [M. Lyon]

lyophil
lyophil, lyophile (li′o-fil, -fil)

A substance that is lyophilic.

lyophilic
lyophilic (li-o-fil′ik)

1. In colloid chemistry, denoting a dispersed phase having a pronounced affinity for the dispersion medium; when the dispersed phase is l., the colloid is usually a reversible one. 2. Denoting a preference for the solvent. SYN: lyotropic. [lyo- + G. phileo, to love]

lyophilization
lyophilization (li-of′i-li-za′shun)

1. The process of isolating a solid substance from solution by freezing the solution and evaporating the ice under vacuum. 2. The process of imparting lyophilic properties to a substance. SYN: freeze-drying.

lyophobe
lyophobe (li′o-fob)

A substance that is lyophobic.

lyophobic
lyophobic (li-o-fo′bik)

1. In colloid chemistry, denoting a dispersed phase having but slight affinity for the dispersion medium; when the dispersed phase is l., the colloid is usually an irreversible one. 2. Denoting a lack of preference or rejection of the solvent. [lyo- + G. phobos, fear]

lyosorption
lyosorption (li-o-sorp′shun)

Adsorption of a liquid on a solid surface.

lyotropic
lyotropic (li-o-trop′ik)

SYN: lyophilic. [lyo- + G. trope, a turning]

lypressin
lypressin (li′pres-in)

Vasopressin-containing lysine in position 8; an antidiuretic and vasopressor hormone. SYN: 8-lysine vasopressin.

lyra
lyra (li′ra)

A lyre-shaped structure. [L. and G. lyre]
l. davidis, lyre of David obsolete terms for commissura fornicis.
l. uterina SYN: palmate folds of cervical canal, under fold.

Lys
Lys

Symbol for lysine or lysyl.

lys- lys-

See lyso-.

lysate
lysate (li′sat)

Material produced by the destructive process of lysis.

lyse
lyse (liz)

To break up, to disintegrate, to effect lysis. SYN: lyze.

lysemia
lysemia (li-se′me-a)

Disintegration or dissolution of red blood cells and the occurrence of hemoglobin in the circulating plasma and in the urine. [lyso- + G. haima, blood]

lysergamide
lysergamide (li-serj′a-mid)

SYN: lysergic acid amide.

lysergic acid
lysergic acid (li-ser′jik)

The d-isomer is a cleavage product of alkaline hydrolysis of ergot alkaloids; occurs as shiny crystals, slightly soluble in water; a psychotomimetic.
l. amide a psychotomimetic agent present in Rivea corymbosa and Ipomoea tricolor; possesses less hallucinogenic potency than does l. diethylamide. SYN: ergine, lysergamide.
l. diethylamide (LSD) peripherally, a serotonin antagonist; 1 to 2 μg per kg induces hallucinatory states of a visual rather than auditory nature; its use may precipitate psychoses; it has been occasionally used in the treatment of chronic alcoholism and psychotic disorders. SYN: lysergide.
l. monoethylamide a psychotomimetic agent present in Rivea corymbosa and Ipomoea tricolor; possesses less hallucinatory potency than does l. diethylamide.

lysergide
lysergide (li-ser′jid)

SYN: lysergic acid diethylamide.

lysergol
lysergol (li-sur-jol)

A semisynthetic ergot alkaloid.

lysin
lysin (li′sin)

1. A specific complement-fixing antibody that acts destructively on cells and tissues; the various types are designated in accordance with the form of antigen that stimulates the production of the l., e.g., hemolysin, bacteriolysin. 2. Any substance that causes lysis.

lysine
lysine (K, Lys) (li′sen)

2,6-Diaminohexanoic acid;the l-isomer is a nutritionally essential α-amino acid of mammals found in many proteins; distinguished by an ε-amino group.
l. decarboxylase an enzyme that catalyzes the decarboxylation of l-l., with the production of cadaverine and CO₂.

lysinemia
lysinemia (li-si-ne′me-a)

See hyperlysinemia.

8-lysine vasopressin
8-lysine vasopressin

SYN: lypressin.

lysinium
lysinium (li-sin′e-um)

The cation form of lysine, either l. (+1) or l. (+2).

lysinogen
lysinogen (li-sin′o-jen)

An antigen that stimulates the formation of a specific lysin.

lysinogenic
lysinogenic (li′si-no-jen′ik)

Having the property of a lysinogen.

lysinuria
lysinuria (li-si-noo′re-a)

The presence of lysine in the urine.

lysis
lysis (li′sis)

1. Destruction of red blood cells, bacteria, and other structures by a specific lysin, usually referred to by the structure destroyed ( e.g., hemolysis, bacteriolysis, nephrolysis); may be due to a direct toxin or an immune mechanism, such as antibody reacting with antigen on the surface of a target cell, usually by binding and activation of a series of proteins in the blood with enzymatic activity (complement system). 2. Gradual subsidence of the symptoms of an acute disease, a form of the recovery process, as distinguished from crisis. [G. dissolution or loosening]
bystander l. complement-mediated l. of nearby cells in the vicinity of a complement activation site.

lyso- lyso-, lys-

Lysis, dissolution. SEE ALSO: lyo-. [G. lysis, a loosening]

lysocephalin
lysocephalin (li-so-sef′a-lin)

A lysophosphatidic acid esterified with serine or ethanolamine, i.e., a lysophosphatidylserine or -ethanolamine; analogous to lysolecithin.

lysogen
lysogen (li′so-jen)

1. That which is capable of inducing lysis. 2. A bacterium in the state of lysogeny. 3. Any antigen that stimulates lysin production. [lysin + G. -gen, producing]

lysogenesis
lysogenesis (li-so-jen′e-sis)

The production of lysins.

lysogenic
lysogenic (li-so-jen′ik)

1. Causing or having the power to cause lysis, as the action of certain antibodies and chemical substances. 2. Pertaining to bacteria in the state of lysogeny.

lysogenicity
lysogenicity (li′so-je-nis′i-te)

The property of being lysogenic.

lysogenization
lysogenization (li′so-je-ni-za′shun, li-soj′e-ni-za′shun)

The process by which a bacterium becomes lysogenic.

lysogeny
lysogeny (li-soj′e-ne)

The phenomenon by which a bacterium is infected by a temperate bacteriophage whose DNA is integrated into the bacterial genome and replicates along with the bacterial DNA but remains latent or unexpressed; triggering of the lytic cycle may occur spontaneously or by certain agents and will result in the production of bacteriophage and lysis of the bacterial cell.

lysokinase
lysokinase (li-so-ki′nas)

Term for activator agents ( e.g., streptokinase, urokinase, staphylokinase) that produce plasmin by indirect or multiple-stage action on plasminogen.

lysolecithin
lysolecithin (li-so-les′i-thin)

A lysophosphatidylcholine; capable of lysing erythrocytes.
l.-lecithin acyltransferase (LLAT) an enzyme that catalyzes the reversible reaction of l. and another phospholipid ( E.G., phosphatidylethanolamine) to form lecithin and lysophosphatidylethanolamine; a major route in the restructuring of lecithin.

lysolecithinase
lysolecithinase (li-so-les′i-thin-as)

SYN: lysophospholipase.

lysophosphatidic acid
lysophosphatidic acid (li′so-fos′fa-tid′ik)

A phosphatidic acid in which only one of the two hydroxyl groups of the glycerophosphate is esterified; most commonly, when carbon-1 of the glycerol moiety is esterified ( e.g., 1-acylglycerol-3-phosphate).
l. acyltransferase, 1-acylglycerol-3-phosphate acyltransferase 1-acylglycerol-3-phosphate acyltransferase.

lysophosphatidylcholine
lysophosphatidylcholine (li′so-fos′fa-ti′dil-ko′len)

A phosphatidylcholine in which a fatty acid has been removed from the C2 position of the glycerol group.

lysophosphatidylserine
lysophosphatidylserine (li′so-fos′fa-ti′dil-ser′en)

Phosphatidylserine from which one fatty acid residue has been removed from the glycerol moiety, typically at carbon-2. Cf.:lysophosphatidic acid.

lysophospholipase
lysophospholipase (li′so-fos′fo-lip′as)

A hydrolase removing the single acyl group from a lysolecithin, producing glycerophosphocholine and the free fatty acid anion. SYN: lecithinase B, lysolecithinase, phospholipase B (1) .

lysosome
lysosome (li′so-som)

A cytoplasmic membrane-bound vesicle measuring 5-8 nm (primary l.) and containing a wide variety of glycoprotein hydrolytic enzymes active at an acid pH; serves to digest exogenous material, such as bacteria, as well as effete organelles of the cells. [lyso- + G. soma, body]
definitive lysosomes SYN: secondary lysosomes.
primary lysosomes lysosomes produced at the Golgi apparatus where hydrolytic enzymes are incorporated; they fuse with phagosomes or pinosomes to become secondary lysosomes.
secondary lysosomes lysosomes in which lysis takes place, owing to the activity of hydrolytic enzymes; they are believed to eventually become residual bodies. SYN: definitive lysosomes, digestive vacuole.

lysostaphin
lysostaphin (li-so-staf′in)

A peptidase enzyme produced by certain strains of staphylococcus microorganisms with antibacterial activity against staphylococci.

lysotype
lysotype (li′so-typ)

A type within a bacterial species determined by its reaction to specific phages. [lyso + type]

lysozyme
lysozyme (li′so-zim)

An enzyme hydrolyzing 1,4-β links between N-acetylmuramic acid and N-acetyl-d-glucosamine, and thus destructive to cell walls of certain bacteria; present in tears and some other body fluids, in egg white, and in some plant tissues; used in the prevention of caries and in the treatment of infant formulas. SYN: mucopeptide glycohydrolase, muramidase.

Lyssavirus
Lyssavirus (lis′a-vi-rus)

A genus of viruses (family Rhabdoviridae) that includes the rabies virus group.
Australian bat L. a species that has caused a fatal rabieslike disease in a woman in Australia.
European bat L. two species (1 & 2) causing rabieslike diseases in humans in Europe; transmitted by bite of insectivorous bats.

lysyl
lysyl (K) (li′sil)

The univalent radical of lysine.
l. hydroxylase an enzyme that acts on specific l. residues in certain proteins ( E.G., collagens) with α-ketoglutarate and O₂ to produce δ-hydroxylysyl residues, succinate, and CO₂; this enzyme, which requires Fe²⁺ and ascorbate, is deficient in Ehlers-Danlos syndrome type VI. SYN: l. 2-oxoglutarate dioxygenase.
l. oxidase an enzyme, which requires Cu²⁺ and O₂, that oxidizes certain l. residues in collagen to allysyl residues and hydroxylysyl residues to hydroxyallysyl residues; this is a required step for the cross-linking (via aldol condensations and Amadori rearrangements) of collagen strands; a lower activity of this enzyme is associated with occipital horn syndrome.
l. 2-oxoglutarate dioxygenase SYN: l. hydroxylase.

lysyl-bradykinin
lysyl-bradykinin (li′sil-brad-e-ki′nin)

SYN: kallidin.

Lythoglyphopsis
Lythoglyphopsis (lith-o-glif-op′-sis)

A genus of amphibious freshwater operculate snails of the family Hydrobiidae (subfamily Hydrobiinae; subclass Prosobranchiata). In the Mekong River delta, L. aperta serves as an intermediate host of the blood fluke, Schistosoma mekongi.

lytic
lytic (lit′ik)

Pertaining to lysis; used colloq. as an abbreviation for osteolytic.

lyxitol
lyxitol (lik′si-tol)

A pentitol (reduced lyxose) occurring in lyxoflavin.

lyxoflavin
lyxoflavin (lik-so-fla′vin)

A compound similar to riboflavin except that d-lyxitol is present in place of the d-ribitol group; present in small quantity in cardiac muscle.

lyxose
lyxose (lik′sos)

An aldopentose; d-l. is epimeric with both d-arabinose and d-xylose; l-l. is epimeric with d-ribose.

lyxulose
lyxulose (liks′u-los)

The 2-keto derivative of lyxose.

lyze
lyze (liz)

SYN: lyse.

l-rhamnose
l-rhamnose (Rha) (ram′nos)

A methylpentose present in a number of plant glycosides, found in free form in poison sumac, in lipopolysaccharides of Enterobacteriaceae, and in rutinose (a disaccharide). SYN: isodulcit.

l-sorbose
l-sorbose (sor′bos)

A very sweet reducing, but not fermentable, 2-ketohexose obtained from the berries of the mountain ash, Sorbus aucuparia (family Rosaceae), and from sorbitol by fermentation with Acetobacter suboxydans; l-sorbose is epimeric with d-fructose and is used in the manufacture of vitamin C. SYN: sorbin, sorbinose, sorbitose.

l-stercobilinogen
l-stercobilinogen (ster′ko-bi-lin′o-jen)

Reduction product of l-urobilinogen, precursor of l-stercobilin in the final stages of bilirubin metabolism; excreted in feces, wherein it is oxidized to stercobilin. SEE ALSO: bilirubinoids.

l-xylulosuria
l-xylulosuria (zi′loo-lo-soo′re-a)

SYN: essential pentosuria.