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Medical Dictionary


poples (pop′lez)
SYN: popliteal fossa. SEE ALSO: popliteal fossa. [L. the ham of the knee]

popliteal (pop-lit′e-al, pop-li-te′al)
Relating to the p. fossa. SYN: popliteus (1) .

popliteus (pop-li-te′us)
1. SYN: popliteal. 2. SYN: popliteal fossa. 3. SYN: p. (muscle). [L.]

Abbreviation for 1,4-bis(5-phenyloxazol-2-yl)benzene, a liquid scintillator.

poppy (pop′e)
SYN: Papaver. p. oil a fixed (drying) oil expressed from the seed of Papaver somniferum; sometimes used in the preparation of liniments and as a solvent of iodine in iodized oil.

population (pop-u-la′shun)
Statistical term denoting all the objects, events, or subjects in a particular class. Cf.:sample. [L. populus, a people, nation]

Abbreviation for problem-oriented record.

See poro-.

porcelain (por′se-lin)
A powder composed of a clay, silica, and a flux that, when mixed with water, forms a paste that is molded to form artificial teeth, inlays, jacket crowns, and dentures. When heated, the materials fuse to form a ceramic.

porcine (por′sin, -sin)
Relating to pigs. [L. porcinus, fr. porcus, a hog]

pore (por) [TA]
1. An opening, hole, perforation, or foramen. A p., meatus, or foramen. SEE ALSO: opening. 2. SYN: sweat p.. SEE ALSO: opening, meatus, foramen. [G. poros, passageway] alveolar pores openings in the interalveolar septa of the lung that permit air flow between adjacent alveoli. dilated p. an enlarged follicular opening of the skin, with a keratinous plug and occasional lanugo or mature hair. external acoustic p., external auditory p. [TA] the orifice of the external acoustic meatus in the tympanic portion of the temporal bone. SYN: porus acusticus externus [TA] , external acoustic aperture&star, external acoustic foramen, external auditory foramen, opening of external acoustic meatus, orifice of external acoustic meatus. gustatory p. SYN: taste p.. interalveolar pores openings in the interalveolar septa of the lung. SYN: Kohn pores. internal acoustic p., auditory p. the inner opening of the internal acoustic meatus on the posterior surface of the petrous part of the temporal bone. SYN: internal acoustic opening [TA] , internal acoustic foramen, internal auditory foramen, opening of internal acoustic meatus, orifice of internal acoustic meatus, porus acusticus internus. Kohn pores SYN: interalveolar pores. nuclear p. an octagonal opening, about 70 nm across, where the inner and outer membranes of the nuclear envelope are continuous. skin p. SYN: sweat p.. slit pores the intercellular clefts between the interdigitating pedicels of podocytes; they are part of the filtration barrier of renal corpuscles. SYN: filtration slits. sweat p. [TA] the surface opening of the duct of a sweat gland. SYN: p. (2) [TA] , porus sudoriferus, porus, skin p.. taste p. [TA] the minute opening of a taste bud on the surface of the oral mucosa through which the gustatory hairs of the specialized neuroepithelial gustatory cells project. SYN: porus gustatorius [TA] , gustatory p..

porencephalia (por′en-se-fa′le-a)
SYN: porencephaly.

porencephalic (por′en-se-fal′ik)
Relating to or characterized by porencephaly. SYN: porencephalous.

porencephalitis (por′en-sef-a-li′tis)
Chronic inflammation of the brain with the formation of cavities in the organ's substance. [G. poros, pore, + enkephalos, brain, + -itis, inflammation]

porencephalous (por-en-sef′a-lus)
SYN: porencephalic.

porencephaly (por-en-sef′a-le)
The occurrence of cavities in the brain substance, communicating usually with the lateral ventricles. SYN: porencephalia, spelencephaly. [G. poros, pore, + enkephalos, brain]

Otto, Austrian bacteriologist, 1879–1968. See P. method, P.-Meier test.

pori (po′ri)
Plural of porus.

poria (por′e-a)
Plural of porion.

Porifera (po-rif′er-a)
The sponges;a phylum of the Metazoa, comprising a group of sessile, aquatic animals possessing an endoskeleton and many branching canals, lined by flagellated collar cells; communication of the canals with the surface is made through many pores or through larger openings and oscula. SEE ALSO: Parazoa. [L. porus, pore, + fero, to bear]

porins (por′inz)
Proteins found in the outer membrane of a double membrane that allow permeability in most small molecules. [G. poros, passageway, + -in]

poriomania (por′e-o-ma′ne-a)
A morbid impulse to wander or journey away from home. [G. poreia, a journey, + mania, frenzy]

porion, pl .poria (por′e-on, -e-a)
The central point on the upper margin of the external auditory meatus; as a cephalometric landmark, it is located in the middle of the metal rods of the cephalometer. [G. poros, a passage]

Acronym for progressive outer retinal necrosis.

pornolagnia (por-no-lag′ne-a)
A rarely used term for sexual attraction toward prostitutes. [G. porne, prostitute, + lagneia, lust]

poro-, por-
1. A pore, a duct, an opening. [G. poros (L. porus), passageway] 2. A going through, a passing through. [G. poreia, a journey, passage] 3. A callus; an induration. [G. poros, a kind of marble, a stone]

porocephaliasis (po′ro-sef-a-li′a-sis)
Infection with a species of the tongue worms Porocephalus. SYN: porocephalosis.

Porocephalidae (po′ro-se-fal′i-de)
A family of parasitic tongue worms (order Porocephalida, phylum Pentastomida) characterized by four hooks arranged in a curved line on either side of the mouth. Adults are found in the lungs of reptiles, and larvae or nymphs are found in the tissues of a great variety of vertebrates, including humans. SEE ALSO: Linguatulidae, Armillifer, Linguatula. [G. poros, pore, + kephale, head]

porocephalosis (po′ro-sef-a-lo′sis)
SYN: porocephaliasis.

Porocephalus (po-ro-sef′a-lus)
A genus of tongue worms of the family Porocephalidae, of which the adult worms or larvae cause porocephaliasis in a number of animal species, including humans. [G. poros, pore, + kephale, head] P. armillatus SYN: Armillifer armillatus.

poroconidium (por′o-ko-nid′e-um)
In fungi, a conidium produced through the microscopic pore of the conidiophore. SYN: porospore.

porokeratosis (po′ro-ker-a-to′sis)
A rare dermatosis in which there is a thickening of the stratum corneum with an annular keratotic rim or cornoid lamella surrounding progressive centrifugal atrophy; cutaneous carcinoma has been reported to arise in the lesions. SYN: Mibelli disease. [G. poros, pore, + keratosis] actinic p. a lesion that occurs on exposed areas of extremities primarily; bears a resemblance to actinic keratosis, but the histologic features are those of p..

poroma (po-ro′ma)
1. SYN: callosity. 2. SYN: exostosis. 3. Induration following a phlegmon. 4. A tumor of cells lining the skin openings of sweat glands. [G. p., callus, fr. poros, stone] eccrine p. a p. or acrospiroma of the eccrine sweat glands, usually occurring on the sole of the foot. as a soft reddish nodule composed of basaloid cells and fibrovascular tissue.

porosis, pl .poroses (po-ro′sis, -sez)
A porous condition. SYN: porosity (1) . [L. porosus, porous] cerebral p. a porous condition of the brain caused by postmortem growth of Clostridium perfringens or other gas-forming organisms in the tissue.

porosity (po-ros′i-te)
1. SYN: porosis. 2. A perforation. [G. poros, pore]

porospore (por′o-spor)
SYN: poroconidium.

porotic (po-rot′ik)
Porous, as in osteoporotic.

porous (po′rus)
Having openings that pass directly or indirectly through the substance.

porphin, porphine (por′fin)
The unsubstituted cyclic tetrapyrrole nucleus that is the basis of the porphyrins. SEE ALSO: porphyrins. Cf.:chlorin, phorbin, corrin. SYN: porphyrin.

porphobilin (por′fo-bi′lin)
General term denoting intermediates between the monopyrrole, porphobilinogen, and the cyclic tetrapyrrole of heme (a porphin derivative). SEE ALSO: bilin.

porphobilinogen (PBG) (por′fo-bi-lin′o-jen)
A porphyrin precursor of porphyrinogens, porphyrins, and heme; found in the urine in large quantities in cases of acute or congenital porphyria. p. synthase a liver enzyme catalyzing the formation of p. and water from two molecules of δ-aminolevulinate, an important reaction in porphyrin biosynthesis; inhibited by lead in cases of lead poisoning; a deficiency of this enzyme results in elevated levels of δ-aminolevulinate and results in neurologic disturbances. SYN: δ-aminolevulinate dehydratase.

porphyria (por-fir′e-a)
A group of disorders involving heme biosynthesis, characterized by excessive excretion of porphyrins or their precursors; may be inherited or may be acquired, as from the effects of certain chemical agents ( e.g., hexachlorobenzene). acute intermittent p., acute p. SYN: intermittent acute p.. δ-aminolevulinate dehydratase p. an inherited disorder in which there is a deficiency of porphobilinogen synthase; δ-aminolevulinate levels are elevated, leading to neurologic disturbances. SYN: porphobilinogen synthase p.. congenital erythropoietic p. [MIM*263700] enhanced porphyrin formation by erythroid cells in bone marrow, leading to severe porphyrinuria, often with hemolytic anemia and persistent cutaneous photosensitivity; caused by a deficiency of uroporphyrinogen III cosynthetase; autosomal recessive inheritance, caused by mutation in the uroporphyrinogen III synthase gene (UROS) on chromosome 10q; there is an overproduction of type I porphyrin isomers. p. cutanea tarda (PCT) [MIM*176090, MIM*176100] familial or sporadic p. characterized by liver dysfunction and photosensitive cutaneous lesions, with bullae, hyperpigmentation, and scleroderma-like changes in the skin and increased excretion of uroporphyrin; caused by a deficiency of uroporphyrinogen decarboxylase induced in sporadic cases by chronic alcoholism; autosomal dominant inheritance in familial cases. SYN: symptomatic p.. p. cutanea tarda hereditaria See p. cutanea tarda. p. cutanea tarda symptomatica See p. cutanea tarda. erythropoietic p. a classification of p. that includes congenital erythropoietic p. and erythropoietic protoporphyria. hepatic p. [MIM*176100.0002] a category of p. that includes p. cutanea tarda, variegate p., and coproporphyria. SYN: p. hepatica. p. hepatica (he-pat′i-ka) SYN: hepatic p.. hepatoerythropoietic p. an autosomal recessive disorder in which there is a deficiency or absence of uroporphyrinogen decarboxylase; results in photosensitivity and excessive hepatic production of 8- and 7-carboxylate porphyrins. intermittent acute p. (IAP) [MIM*176000] p. caused by hepatic overproduction of δ-aminolevulinic acid, with greatly increased urinary excretion of it and of porphobilinogen, and some increase of uroporphyrin, due to a deficiency of porphobilinogen deaminase; characterized by intermittent acute attacks of hypertension, abdominal colic, psychosis, and polyneuropathy, but with no photosensitivity; autosomal dominant inheritance, caused by mutation in the human porphobilinogen deaminase gene on 11q24; exacerbation caused by ingestion of certain drugs ( e.g., barbiturates). SYN: acute intermittent p., acute p.. ovulocyclic p. acute episodic exacerbations of p. occurring in the premenstrual period. porphobilinogen synthase p. SYN: δ-aminolevulinate dehydratase p.. South African type p. SYN: variegate p.. symptomatic p. SYN: p. cutanea tarda. variegate p. (VP) [MIM*176200] p. characterized by abdominal pain and neuropsychiatric abnormalities, by dermal sensitivity to light and mechanical trauma, by increased fecal excretion of proto- and coproporphyrin, and by increased urinary excretion of δ-aminolevulinic acid, porphobilinogen, and porphyrins; due to a deficiency of protoporphyrinogen oxidase; autosomal dominant inheritance, caused by mutation in the gene for protoporphyrinogen oxidase (PPOX) on chromosome 1q. SYN: protocoproporphyria hereditaria, South African type p..

porphyrin (por′fi-rin)
SYN: porphin.

porphyrinogens (por-fi-rin′o-jenz)
Intermediates in the biosynthesis of heme, as follows: four porphobilinogens condense to form uroporphyrinogens I and III (giving rise to side products uroporphyrins I and III) which are decarboxylated to form coproporphyrinogens I and III (giving rise to side products coproporphyrins I and III); coproporphyrinogen III is oxidized to protoporphyrinogen III (IX), which is then oxidized to form protoporphyrin III (IX) (this last intermediate adds ferrous iron to yield heme); certain p. are elevated in certain porphyrias.

porphyrinopathy (por′fir-in-op′a-the)
A syndrome that results from abnormal porphyrin metabolism such as acute porphyria. SYN: porphyrism. [porphyrin + G. pathos, disease]

porphyrins (por′fi-rinz)
Pigments widely distributed throughout nature ( e.g., heme, bile pigments, cytochromes) consisting of four pyrroles joined in a ring (porphin) structure. They are substitution products of porphin (porphyrin) and comprise several varieties, differing for the most part in the side chains (methyl, ethyl, vinyl, formyl, carboxyethyl, carboxymethyl, etc.) present at the eight available positions on the pyrrole rings. Depending on the nature of the side chains, the prefixes dentero-, etio-, meso-, proto-, etc., are attached to p.; distribution within each class is given by type I, II, III, and IV. P. combine with various metals (iron, copper, magnesium, etc.) to form metalloporphyrins, and with nitrogenous substances.

porphyrinuria (por′fir-i-noo′re-a)
Excretion of porphyrins and related compounds in the urine. SYN: porphyruria, purpurinuria.

SYN: porphyrinopathy.

porphyrization (por′fi-ri-za′shun)
Grinding in a mortar (formerly on a slab of porphyry).

Porphyromonas (por′fir-o-mon′as)
A genus of small anaerobic Gram-negative nonmotile cocci and usually short rods that produce smooth, gray to black pigmented colonies the size of which varies with the species. In humans, they are found as part of the normal flora in the oropharynx, including gingival crevices, and in the vaginal and intestinal tracts. The type species is P. asaccharolytica. P. asaccharolytica a species that rarely causes infections independently but is an important component of mixed infections associated with oral, genitourinary, and intra-abdominal abscesses, as well as in infectious associated with impaired circulation and diabetic gangrene.

porphyruria (por-fi-roo′re-a)
SYN: porphyrinuria.

Edoardo, Italian obstetrician, 1842–1902. See P. hysterectomy.

port (port)
SYN: portal. ancillary ports during endoscopic surgery, the placement of more than one entry site to allow insertion of instruments other than the endoscope.

porta, pl .portae (por′ta, -te)
1. SYN: hilum (1) . 2. SYN: interventricular foramen. [L. gate] p. hepatis [TA] a transverse fissure on the visceral surface of the liver between the caudate and quadrate lobes, lodging the portal vein, hepatic artery, hepatic nerve plexus, hepatic ducts, and lymphatic vessels. SYN: caudal transverse fissure, portal fissure. p. lienis SYN: splenic hilum. p. pulmonis SYN: hilum of lung. p. renis SYN: hilum of kidney.

Port-a-Cath (port′a-kath)
A long-term central venous catheter with subcutaneous port(s). [brand name]

portacaval (por′ta-ka′val)
Concerning the portal vein and the inferior vena cava.

portal (por′tal)
1. Relating to any porta or hilus, specifically to the porta hepatis and the p. vein. 2. The point of entry into the body of a pathogenic microorganism. SYN: port. [L. portalis, pertaining to a porta (gate)] anterior intestinal p. SYN: fovea cardiaca. posterior intestinal p. in young embryos, the communications from the midgut to the hindgut.

Curt C., U.S. biochemist, *1914. See P.-Silber chromogens, under chromogen, P.-Silber reaction, P.-Silber chromogens test.

Thomas C., British scientist, 1860–1933. See Ferry-P. law.

William H., Irish surgeon, 1790–1861. See P. fascia.

portio, pl .portiones (por′she-o, -o′nez)
A part. [L. portion] p. intermedia SYN: intermediate nerve. p. major nervi trigemini SYN: sensory root of trigeminal nerve. p. minor nervi trigemini SYN: motor root of trigeminal nerve. p. supravaginalis cervicis [TA] SYN: supravaginal part of cervix. p. vaginalis cervicis [TA] SYN: vaginal part of cervix.

portion (por′shun)
Part or division. accessory p. of spinal accessory nerve SYN: cranial root of accessory nerve. anterior p. of left medial segment IV of liver [TA] the part of the medial segment of the liver that includes the quadrate lobe. SYN: quadrate part of liver [TA] , pars quadrata hepatis. mesenteric p. of small intestine the freely movable p. of the small intestine supplied with a mesentery, comprising the jejunum and ileum. SYN: intestinum tenue mesenteriale. subcutaneous p. of external anal sphincter SYN: subcutaneous part of external anal sphincter. See external anal sphincter.

portiplexus (por-ti-plek′sus)
The union of the choroid plexus of the lateral ventricle with that of the third ventricle at the interventricular foramen (of Monro).

Portal. [L. porta, gate]

portobilioarterial (por′to-bil′e-o-ar-ter′e-al)
Relating to the portal vein, biliary ducts, and hepatic artery, which have similar distributions. SEE ALSO: portal triad.


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