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Medical Dictionary


capacitance (ka-pas′i-tans)
The quantity of electric charge that may be stored upon a body per unit electric potential; expressed in farads, abfarads, or statfarads.

capacitation (ka-pas′i-ta′shun)
C. is a process whereby the glycoprotein coat is modified and seminal proteins are removed from the surface of the sperm. There are no morphologic changes. C. occurs in in vitro fertilization; after c., the acrosomal reaction can occur. [L. capacitas, fr. capax, capable of]

capacitor (ka-pas′i-ter, -tor)
A device for holding a charge of electricity. SYN: condenser (4) .

capacity (ka-pas′i-te)
1. The potential cubic contents of a cavity or receptacle. 2. Power to do. SEE ALSO: volume. [L. capax, able to contain; fr. capio, to take] buffer c. the amount of hydrogen ion (or hydroxyl ion) required to bring about a specific pH change in a specified volume of a buffer. SEE ALSO: buffer value. carrying c. an estimate of the number of people that a region, a nation, or the planet can sustain. cranial c. the cubic content of the skull obtained by determining the cubage of small shot, seeds, or beads required to fill the skull. diffusing c. (symbol, D, followed by subscripts indicating location and chemical species) the amount of oxygen taken up by pulmonary capillary blood per minute per unit average oxygen pressure gradient between alveolar gas and pulmonary capillary blood; units are: ml/min/mm Hg; also applied to other gases such as carbon monoxide, which is used in the standard clinical measure of diffusing c.. forced vital c. (FVC) vital c. measured with the subject exhaling as rapidly as possible; data relating volume, expiratory flow, and time form the basis for other pulmonary function tests, e.g., flow-volume curve, forced expiratory volume, forced expiratory time, forced expiratory flow. functional residual c. (FRC) the volume of gas remaining in the lungs at the end of a normal expiration; it is the sum of expiratory reserve volume and residual volume. SYN: functional residual air. heat c. the quantity of heat required to raise the temperature of a system 1°C. SYN: thermal c.. inspiratory c. the volume of air that can be inspired after a normal expiration; it is the sum of the tidal volume and the inspiratory reserve volume. SYN: complementary air. iron-binding c. (IBC) the c. of iron-binding protein in serum (transferrin) to bind serum iron. maximum breathing c. (MBC) SYN: maximum voluntary ventilation. oxygen c. the maximum quantity of oxygen that will combine chemically with the hemoglobin in a unit volume of blood; normally it amounts to 1.34 ml of O2 per g of Hb or 20 ml of O2 per 100 ml of blood. residual c. SYN: residual volume. respiratory c. SYN: vital c.. thermal c. SYN: heat c.. total lung c. (TLC) the inspiratory c. plus the functional residual c.; i.e., the volume of air contained in the lungs at the end of a maximal inspiration; also equals vital c. plus residual volume. vital c. (VC) the greatest volume of air that can be exhaled from the lungs after a maximum inspiration. SYN: respiratory c..

capactins (kap-ak′tinz)
A class of proteins capping the ends of actin filaments.

Acronym for continuous ambulatory peritoneal dialysis.

Jean Marie Joseph, French psychiatrist, 1873–1950. See C. phenomenon, C. syndrome.

capillarectasia (kap′i-lar-ek-ta′ze-a)
Rarely used term for dilation of the capillary blood vessels. [capillary + G. ektasis, extension]

Capillaria (kap-i-la′re-a)
A genus of aphasmid nematode worms, characterized by threadlike appearance; related to Trichuris. [L. capillaris, fr. capillus, hair] C. hepatica species of threadworm that infects the liver in rodents; occasionally reported from humans. C. philippinensis a species of threadworm that has been implicated as a cause of intestinal capillariasis among northern Philippine fishermen.

capillariasis (kap′i-lar-i′a-sis)
A disease caused by infection with nematodes of the genus Capillaria. intestinal c. a spruelike diarrheal disease caused by infection with Capillaria philippinensis, large populations of which are built up by internal autoinfection in the intestinal mucosa; characterized by abdominal pain, edema, diarrhea, cachexia, hypoproteinemia, hypotension, cardiac failure, and hyporeflexia; severe infection is often manifested as a fulminating disorder that may be fatal.

capillariomotor (kap-i-lar′e-o-mo′tor)
Vasomotor, with special reference to the capillaries.

capillarioscopy (kap′i-lar-e-os′ko-pe)
Viewing the cutaneous capillaries at the base of the fingernail through the low power of the microscope. SYN: capillaroscopy, microangioscopy.

capillaritis (kap′i-lar-i′tis)
Inflammation of a capillary or capillaries.

capillarity (kap-i-lar′i-te)
The rise of liquids in narrow tubes or through the pores of a loose material, as a result of capillary action.

capillaron (kap′i-la-ron)
An anatomical module composed of parenchymal cells together with their blood capillaries and extracapillary fluid in a compliant capsule; functions as a hydraulic unit that provides a theoretical basis for proposing that blood flow is regulated at the capillary.

capillaropathy (kap′i-la-rop′a-the)
Any disease of the capillaries, often applied to vascular changes in diabetes mellitus. SYN: microangiopathy. [capillary + G. pathos, disease]

capillaroscopy (kap′i-lar-os′ko-pe)
SYN: capillarioscopy.

capillary (kap′i-lar-e) [TA]
1. Resembling a hair; fine; minute. 2. A c. vessel; e.g., blood c., lymph c.. SYN: vas capillare [TA] , c. vessel. 3. Relating to a blood or lymphatic c. vessel. [L. capillaris, relating to hair] arterial c. a c. opening from an arteriole or metarteriole. bile c. SYN: biliary canaliculus. blood c. (symbol c, as a subscript) a vessel whose wall consists of endothelium and its basement membrane; its diameter, when the c. is open, is about 8 μm; with the electron microscope, fenestrated capillaries and continuous capillaries are distinguished. continuous c. a c. in which small vesicles (caveolae) are numerous and pores are absent. fenestrated c. a c., found in renal glomeruli, intestinal villi, and endocrine glands, in which ultramicroscopic pores of variable size occur; usually these are closed by a delicate diaphragm, although diaphragms are lacking in at least some renal glomerular capillaries. lymph c. the beginning of the lymphatic system of vessels; it is lined with a highly attenuated endothelium with poorly developed basement membrane and a lumen of variable caliber. See lacteal (2) . sinusoidal c. SYN: sinusoid. venous c. a c. opening into a venule.

capita (kap′i-ta)
Plural of caput.

capitate (kap′i-tat) [TA]
1. The largest of the carpal bones; located in the distal row. SYN: os capitatum [TA] , c. bone, magnum, os magnum. 2. Head-shaped; having a rounded extremity. [L. caput (capit-), head]

capitation (kap-i-ta′shun)
A system of medical reimbursement wherein the provider is paid an annual fee per covered patient by an insurer or other financial source, which aggregate fees are intended to reimburse all provided services. [L.L. capitatio, fr. caput, head]]

capitellum (kap-i-tel′um)
1. SYN: capitulum (1) . 2. SYN: capitulum of humerus. [L. dim. of caput, head]

capitopedal (kap-i-to-ped′al)
Relating to the head and the feet. [L. caput, head, + pes (ped-), foot]

capitula (ka-pit′u-la)
Plural of capitulum.

capitular (ka-pit′u-lar)
Relating to a capitulum.

capitulum, pl .capitula (ka-pit′u-lum, -la) [TA]
1. [NA] A small head or rounded articular extremity of a bone. SYN: capitellum (1) . SEE ALSO: caput. 2. The bloodsucking, probing, sensing, and holdfast mouthparts of a tick, including the basal supporting structure; relative size and shape of mouthparts forming the c. are characteristic for the genera of hard ticks. [L. dim. of caput, head] c. humeri [TA] SYN: c. of humerus. c. of humerus [TA] the small rounded eminence on the lateral half of the distal end of the humerus for articulation with the radius. SYN: c. humeri [TA] , capitellum (2) , little head of humerus.

Anthony, British physician, 1907–1976. See C. nodules, under nodule, C. syndrome.

Capnocytophaga (kap′no-si-tof′a-ga)
A genus of Gram-negative, fusiform bacteria that require carbon dioxide for growth and exhibits gliding motility; associated with human periodontal disease; type species is C. ochracea (formerly Bacteroides ochracea). C. canimorsus a bacterial species linked to infections from dog bites (including bacteremia, endocarditis, and meningitis. Formerly designated DF-2 by the CDC. These infections usually occur in patients with impaired immune systems.

capnogram (kap′no-gram)
A continuous record of the carbon dioxide content of expired air. [G. kapnos, smoke, + gramma, something written]

capnograph (kap′no-graf)
Instrument by which a continuous graph of the carbon dioxide content of expired air is obtained.

capnometry (cap′-nom-e-tre)
Measurement of CO2 in the proximal airway during inspiration and expiration. End tidal CO2 (or CO2 at the end of exspiration) is particularly useful clinically.

1. Covering. 2. The aggregation at one end of a cell of surface antigens that have been bound and cross-linked by antibodies; this cap is then endocytosed by the cell. direct pulp c. a procedure for covering and protecting an exposed vital pulp. indirect pulp c. the application of a suspension of calcium hydroxide to a thin layer of dentin overlying the pulp (near exposure) in order to stimulate secondary dentin formation and protect the pulp.

Joseph A., U.S. physician, 1872–1964. See C. reflex.

caprate (kap′rat)
A salt or ester of capric acid.

capreomycin sulfate (kap′re-o-mi′sin)
Sulfate salt of the cyclic peptide antibiotic obtained from Streptomyces capreolus, used in the treatment of tuberculosis.

capriloquism (ka-pril′o-kwizm)
SYN: egophony. [L. caper, goat, + loquor, to speak]

caprin (kap′rin)
One of the substances found in butter upon which its flavor depends. SYN: decanoin, glyceryl tricaprate.

caprine (ka′prin)
Relating to goats; goatlike. [L. caprinus, of goats]

Capripoxvirus (kap′ri-poks-vi′rus)
The genus of Poxviridae that includes the viruses of sheep-pox and goatpox. [L. capra, she-goat, + virus]

caprizant (kap′ri-zant)
Bounding; leaping; denoting a form of pulse beat. [Fr., leaping, fr. L. caper, goat]

caproate (kap′ro-at)
1. A salt or ester of n-caproic acid. 2. USAN-approved contraction for hexanoate, CH3(CH2)4COO−.

caproyl (kap′ro-il)
The acyl radical of caproic acid. SYN: hexanoyl.

caproylate (kap′ro-i-lat)
A salt or ester of caproic acid. SYN: hexanoate.

caprylate (kap′ri-lat)
A salt or ester of caprylic acid. SYN: octanoate.

caprylic acid (kap-ril′ik)
A fatty acid found among the hydrolysis products of fat in butter, coconut oil, and other substances. SYN: octanoic acid.

capsaicin (kap-sa′i-sin)
Alkaloidal principle in the fruits of various species of Capsicum, with the same uses as capsicum. It depletes substance P from sensory nerve endings; Sometimes used for pain in postherpetic neuralgia.

capsicin (kap′si-sin)
A yellowish red oleoresin containing the active principle of capsicum.

capsicum (kap′si-kum)
Cayenne, African, or red pepper, the dried ripe fruit of C. frutescens (family Solanaceae); used as a carminative, gastrointestinal stimulant, and externally as a rubefacient.

capsid (kap′sid)
See virion.

capsomer, capsomere (kap′so-mer)
A subunit of the protein coat or capsid of a virus particle. SEE ALSO: hexon, penton, virion.

capsula, gen. and pl. capsulae (kap′soo-la, -le) [TA]
1. SYN: capsule (2) . [L. dim. of capsa, a chest or box] c. adiposa perirenalis [TA] c. adiposa renis SYN: paranephric fat. c. articularis [TA] SYN: joint capsule. c. articularis cricoarytenoidea [TA] SYN: capsule of cricoarytenoid joint. c. articularis cricothyroidea [TA] SYN: capsule of cricothyroid joint. c. bulbi SYN: fascial sheath of eyeball. c. cordis SYN: pericardium. c. externa [TA] SYN: external capsule. c. extrema [TA] SYN: extreme capsule. c. fibrosa SYN: fibrous capsule. c. fibrosa glandulae thyroideae [TA] SYN: fibrous capsule of thyroid gland. c. fibrosa perivascularis SYN: fibrous capsule of liver (1) . c. fibrosa renis [TA] SYN: fibrous capsule of kidney. c. glomeruli SYN: glomerular capsule. c. interna [TA] SYN: internal capsule. c. lentis [TA] SYN: capsule of lens. c. lienis [TA] SYN: fibrous capsule of spleen. c. vasculosa lentis in the embryo, the vascular mesenchymal capsule that invests the lens of the eye; the vessels of the deep part of the capsule are branches of the hyaloid artery; those of the superficial part are derived from the anterior ciliary arteries; normally all the vessels are atrophied by the end of the eighth month of intrauterine life.

capsular (kap′soo-lar)
Relating to any capsule.

capsulation (kap-soo-la′shun)
Enclosure in a capsule.

capsule (kap′sool) [TA]
1. A membranous structure, usually dense collagenous connective tissue, that envelops an organ, a joint, or any other part. 2. An anatomic structure resembling a c. or envelope. SYN: capsula (1) [TA] . 3. A fibrous tissue layer enveloping an organ or a tumor, especially if benign. 4. A solid dosage form in which a drug is enclosed in either a hard or soft soluble container or “shell” of a suitable form of gelatin. 5. A hyaline polysaccharide coating around a fungal or bacterial cell. Bacteria may also have a polypeptide c. or a slime layer around the cell. [L. capsula, dim. of capsa, box] adipose c. SYN: paranephric fat. adrenal c. SYN: suprarenal gland. articular c. joint c.. atrabiliary c. SYN: suprarenal gland. auditory c. SYN: otic c.. bacterial c. a layer of slime of variable composition which covers the surface of some bacteria; capsulated cells of pathogenic bacteria are usually more virulent than cells without capsules because the former are more resistant to phagocytic action. Bonnet c. the anterior part of the vagina bulbi. Bowman c. SYN: glomerular c.. brood capsules small hollow projections from the lining membrane of a hydatid cyst from which the scoleces arise. cartilage c. the more intensely basophilic and metachromatic matrix in hyaline cartilage surrounding the lacunae of chrondrocytes resulting from relatively high concentrations of chondromuco protein. SYN: territorial matrix. cricoarytenoid articular c. SYN: c. of cricoarytenoid joint. c. of cricoarytenoid joint [TA] the c. enclosing the joint between the arytenoid and cricoid cartilages. SYN: capsula articularis cricoarytenoidea [TA] , cricoarytenoid articular c.. cricothyroid articular c. SYN: c. of cricothyroid joint. c. of cricothyroid joint [TA] the c. enclosing the cricothyroid joint. SYN: capsula articularis cricothyroidea [TA] , cricothyroid articular c.. Crosby c. an attachment to the end of a flexible tube, used for peroral biopsy of the small intestine, by which a piece of mucosa is sucked into an opening in the c. and cut off. crystalline c. SYN: c. of lens. external c. [TA] a thin lamina of white substance separating the claustrum from the putamen. It joins the internal c. at either extremity of the putamen, forming a c. of white matter external to the lenticular nucleus. SYN: capsula externa [TA] , periclaustral lamina. extreme c. [TA] the layer of white matter separating the claustrum from the cortex of the insula, probably representing largely corticopetal and corticofugal fibers of the insular cortex. SYN: capsula extrema [TA] . eye c. SYN: fascial sheath of eyeball. fatty renal c. SYN: paranephric fat. fibrous c. [TA] any fibrous envelope of a part; the fibrous c. of an organ. SYN: stratum fibrosum [TA] , tunica fibrosa [TA] , capsula fibrosa, stratum fibrosum capsulae articularis. fibrous articular c. SYN: fibrous layer of joint c.. fibrous c. of kidney [TA] a fibrous membrane ensheathing the kidney. SYN: capsula fibrosa renis [TA] , tunica fibrosa renis. fibrous c. of liver [TA] 1. a layer of connective tissue ensheathing the outer surface of the liver and also the hepatic artery, portal vein, and bile ducts as these ramify within the liver; SYN: capsula fibrosa perivascularis, perivascular fibrous c.. 2. connective tissue c. surrounding the outer surface of the liver, but continuous with septae of some animals, e.g., pigs, which divide parenchyme into lobule, and with the perivascular fibrous c. at the porta hepatis. SYN: tunica fibrosa hepatis [TA] , Glisson c.. fibrous c. of parotid gland SYN: parotid fascia. fibrous c. of spleen [TA] the fibrous c. of the spleen, containing collagen, elastic fibers, and smooth muscle. SYN: capsula lienis [TA] , tunica fibrosa splenis&star, tunica fibrosa lienis, tunica propria lienis. fibrous c. of thyroid gland [TA] the fibrous sheath of the thyroid gland. SYN: capsula fibrosa glandulae thyroideae [TA] . Gerota c. SYN: renal fascia. Glisson c. SYN: fibrous c. of liver (2) . glomerular c. [TA] the expanded beginning of a nephron composed of an inner and outer layer: the visceral layer consists of podocytes that surround a tuft of capillaries (glomerulus); the parietal layer is simple squamous epithelium that becomes cuboidal at the tubular pole. SYN: Bowman c., capsula glomeruli, malpighian c. (1) , Müller c.. internal c. [TA] a massive layer (8–10 mm thick) of white matter separating the caudate nucleus and thalamus (medial) from the more laterally situated lentiform nucleus (globus pallidus and putamen). It consists of 1) fibers ascending from the thalamus to the cerebral cortex that compose, among others, the visual, auditory, and somatic sensory radiations, and 2) fibers descending from the cerebral cortex to the thalamus, subthalamic region, midbrain, hindbrain, and spinal cord. The internal c. is the major route by which the cerebral cortex is connected with the brainstem and spinal cord. Laterally and superiorly it is continuous with the corona radiata which forms a major part of the cerebral hemisphere's white matter; caudally and medially it continues, much reduced in size, as the crus cerebri which contains, among others, corticospinal fibers. On horizontal section it appears in the form of a V opening out laterally; the V's obtuse angle is called genu (knee); its anterior and posterior limbs, respectively, the crus anterior and crus posterior. The internal c. consists of an anterior limb [TA], genu of internal c. [TA], posterior limb [TA], retrolentiform (or retrolenticular) limb [TA], and sublentiform (or sublenticular) limb [TA]. SYN: capsula interna [TA] . joint c. [TA] a sac enclosing the articulating ends of the bones participating in a synovial joint, formed by an outer fibrous articular c. and an inner synovial membrane. SYN: capsula articularis [TA] , articular c.&star. lens c. SYN: c. of lens. c. of lens [TA] the c. enclosing the lens of the eye. SYN: capsula lentis [TA] , crystalline c., lens c., lenticular c., phacocyst. lenticular c. SYN: c. of lens. malpighian c. 1. SYN: glomerular c.. 2. a thin fibrous membrane enveloping the spleen and continued over the vessels entering at the hilus. Müller c. SYN: glomerular c.. nasal c. the cartilage around the developing nasal cavity of the embryo. optic c. the concentrated zone of mesenchyme around the developing optic cup; the primordium of the sclera of the eye. otic c. the cartilage c. surrounding the inner ear mechanism; in elasmobranchs, it remains cartilaginous in the adult; in the embryos of higher vertebrates, it is cartilaginous at first but later becomes bony (at approximately 23 weeks in humans). SYN: auditory c.. perirenal fat c. SYN: paranephric fat. perivascular fibrous c. SYN: fibrous c. of liver (1) . radiotelemetering c. an instrument that transmits measurements by radio impulses, from within the body; e.g., measurements of pressure from within the small bowel. SYN: radiopill. seminal c. SYN: seminal gland. suprarenal c. SYN: suprarenal gland. Tenon c. SYN: fascial sheath of eyeball.

Removal of a capsule, as around an implant or scarred tissue.

capsulitis (kap′soo-li′tis)
Inflammation of the capsule of an organ or part, as of the liver, the lens of the eye, or surrounding a joint. adhesive c. a condition in which there is limitation of motion in a joint due to inflammatory thickening of the capsule, a common cause of stiffness in the shoulder. SYN: frozen shoulder. hepatic c. SYN: perihepatitis.

capsulolenticular (kap′soo-lo-len-tik′u-lar)
Referring to the lens of the eye and its capsule.


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