| portal cirrhosis | Synonym: Laennec's cirrhosis. (05 Mar 2000) |
|---|---|
| portal fissure | 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. Synonym: caudal transverse fissure, portal fissure. (05 Mar 2000) |
| portal hypertension | Any increase in the portal vein (in the liver) pressure due to anatomic or functional obstruction (for example alcoholic cirrhosis) to blood flow in the portal venous system. Indicators of portal hypertension are: oesophageal varices, haemorrhoids, enlarged veins on the anterior abdominal wall (caput Medusae) and ascites (fluid within the abdominal cavity). (27 Sep 1997) |
| portal hypertension: classification | <radiology> Presinusoidal, extrahepatic: portal vein obstruction (extrinsic compression, phlebitis, OC, coagulopathy, tumour invasion, pancreatitis, neonatal omphalitis), dynamic: traumatic/neoplastic arterioportal fistula, segmental portal hypertension: splenic/superior mesenteric vein occlusion, intrahepatic (obstruction of portal venules): congenital hepatic fibrosis, primary biliary cirrhosis, sarcoid, myelofibrosis, schistosomiasis, idiopathic noncirrhotic fibrosis, Wilson disease, reticuloendotheliosis, Felty syndrome, chronic malaria, toxic fibrosis (arsenic, copper, PVC vapors) sinusoidal, cirrhosis, sclerosing cholangitis postsinusoidal, Budd-Chiari syndrome, constrictive pericarditis, congestive heart failure (12 Dec 1998) |
| portal hypophysial 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) |
| portal lobule 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 centre and three or more venae centrales hepatis at its periphery. (05 Mar 2000) |
| portal pressure | The venous pressure measured in the portal vein. (12 Dec 1998) |
| portal pyaemia | Suppurative pylephlebitis. (05 Mar 2000) |
| 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) |
| 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) |