| IAC | image analysis cytometry; ineffective airway clearance; internal auditory canal; interposed abdomina... |
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| ITC | imidazolyl-thioguanine chemotherapy; Interagency Testing Committee; in the canal [hearing aid] |
| MEC | median effective concentration; middle ear canal; middle ear cell; minimum effective concentration |
| RC | an electronic circuit containing a resistor and capacitor in series; radiocarpal; reaction center; r... |
| RCT | radiotherapy and chemotherapy; randomized clinical trial; randomized controlled trial; registered ca... |
| portal system | A system of vessels in which blood, after passing through one capillary bed, is conveyed through a second set of capillaries before it returns to the systemic circulation. It pertains especially to the hepatic portal system. (12 Dec 1998) |
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| portal-systemic anastomoses | Naturally-occurring venous communications between tributaries of the portal venous system and tributaries of the systemic venous system. The major portal-systemic anastomoses include: 1) oesophageal branches of left gastric vein with oesophageal veins, 2) superior rectal vein with middle and inferior rectal veins, 3) paraumbilical veins with subcutaneous veins of anterior abdominal wall, 4) retroperitoneal veins with venous branches of veins of the colon and bare area of the liver, and 5) a patent ductus venosus connecting left branch of portal vein to inferior vena cava (rare). These anastomoses are important clinically, providing collateral circulation during portal obstruction or hypertension, at which time they may become varicose. See: caput medusae, oesophageal varices, haemorrhoids. Surgically-created communications between the portal vein and the inferior vena cava or their tributaries, to relieve portal hypertension. Synonym: portacaval anastomoses. (05 Mar 2000) |
| portal-systemic encephalopathy | An encephalopathy associated with cirrhosis of the liver, attributed to the passage of toxic nitrogenous substances from the portal to the systemic circulation; cerebral manifestations may include coma. Synonym: hepatic encephalopathy. (05 Mar 2000) |
| portal triad | Branches of the portal vein, hepatic artery, and the biliary ducts bound together in the perivascular fibrous capsule or portal tract as they ramify within the substance of the liver. Synonym: hepatic triad, triad. (05 Mar 2000) |
| portal vein | <anatomy, vein> A large vein that carries blood from the stomach and intestines to the liver. (09 Oct 1997) |
| posterior branch of right branch of portal vein | <anatomy, vein> Posterior segmental branch of portal vein; branch to posterior segments of right lobe of liver. Synonym: ramus posterior rami dextri venae portae hepatis. (05 Mar 2000) |
| posterior intestinal portal | In young embryos, the communications from the midgut to the hindgut. (05 Mar 2000) |
| prominent portal vein radicles | <radiology> Seen in acute hepatitis (12 Dec 1998) |
| hepatic portal system | A venous portal system in which the portal vein receives blood via its tributaries from the capillaries of most of the abdominal viscera and drains it into the hepatic sinusoids. (05 Mar 2000) |
| hepatic portal vein | <anatomy, vein> A large vein that carries blood from the stomach and intestines to the liver. (09 Oct 1997) |
| hypertension, portal | Abnormally increased pressure in the portal venous system; frequently seen in cirrhosis of the liver and in other conditions which cause obstruction of the portal vein. (12 Dec 1998) |
| hypophysial portal circulation | A capillary network that carries hypophyseotropic hormones from the hypothalamus, where they are secreted into blood, to their sites of action in the anterior hypophysis. See: portal circulation, hypophysis, hypothalamus. Synonym: hypophyseoportal system, hypophysial portal circulation, hypophysial portal system, hypophysioportal system, hypothalamohypophysial portal circulation, hypothalamohypophysial portal system. (05 Mar 2000) |
| hypophysial portal system | A capillary network that carries hypophyseotropic hormones from the hypothalamus, where they are secreted into blood, to their sites of action in the anterior hypophysis. See: portal circulation, hypophysis, hypothalamus. Synonym: hypophyseoportal system, hypophysial portal circulation, hypophysial portal system, hypophysioportal system, hypothalamohypophysial portal circulation, hypothalamohypophysial portal system. (05 Mar 2000) |
| hypothalamohypophysial portal circulation | A capillary network that carries hypophyseotropic hormones from the hypothalamus, where they are secreted into blood, to their sites of action in the anterior hypophysis. See: portal circulation, hypophysis, hypothalamus. Synonym: hypophyseoportal system, hypophysial portal circulation, hypophysial portal system, hypophysioportal system, hypothalamohypophysial portal circulation, hypothalamohypophysial portal system. (05 Mar 2000) |
| hypothalamohypophysial portal system | A capillary network that carries hypophyseotropic hormones from the hypothalamus, where they are secreted into blood, to their sites of action in the anterior hypophysis. See: portal circulation, hypophysis, hypothalamus. Synonym: hypophyseoportal system, hypophysial portal circulation, hypophysial portal system, hypophysioportal system, hypothalamohypophysial portal circulation, hypothalamohypophysial portal system. (05 Mar 2000) |