| port-wine mark | Flame nevus, a large congenital vascular nevus having a purplish colour; it is usually found on the head and neck and persists throughout life. See: Sturge-Weber syndrome. Synonym: port-wine mark, port-wine stain. (05 Mar 2000) |
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| port-wine stain | <technique> A mark on the skin that resembles port wine (porto) in its rich ruby red colour. Due to an abnormal aggregation of capillaries, a port-wine stain is a type of haemangioma. It occurs on the face as a sign of sturge-weber syndrome. (12 Dec 1998) |
| porta | Origin: L, a gate. See Port a hole. <anatomy> The part of the liver or other organ where its vessels and nerves enter; the hilus. The foramen of Monro. Source: Websters Dictionary (01 Mar 1998) |
| porta hepatis | 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) |
| porta lienis | A fissure on the gastric surface of the spleen, giving passage to the splenic vessels and nerves. Synonym: hilum splenicum, hilum lienis, porta lienis. (05 Mar 2000) |
| porta pulmonis | A wedge-shaped depression on the mediastinal surface of each lung, where the bronchus, blood vessels, nerves, and lymphatics enter or leave the viscus. Synonym: hilum pulmonis, porta pulmonis. (05 Mar 2000) |
| porta renis | The depression on the medial border of the kidney through which pass the segmental renal vessels and renal nerves and where the apex of the renal pelvis occurs. Synonym: hilum renalis, porta renis. (05 Mar 2000) |
| portable | 1. Capable of being borne or carried; easily transported; conveyed without difficulty; as, a portable bed, desk, engine. 2. Possible to be endured; supportable. "How light and portable my pain seems now!" (Shak) Portable forge. See Forge. Portable steam engine. See Steam engine. Origin: L. Portabilis, fr. Portare to carry: cf. F. Portable. See Port demeanor. Source: Websters Dictionary (01 Mar 1998) |
| portable radiography | Making radiographic films of a patient confined to bed by taking a movable X-ray machine to the room. Synonym: bedside radiography. (05 Mar 2000) |
| portacaval | Concerning the portal vein and the inferior vena cava. (05 Mar 2000) |
| portacaval 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) |
| portacaval shunt | Surgical anastomosis between portal and systemic veins, surgical anastomosis between the portal vein and the vena cava, as in an Eck fistula. (05 Mar 2000) |
| portacaval shunt, surgical | Surgical portasystemic shunt between the portal vein and inferior vena cava. (12 Dec 1998) |
| portage group | <geology> A subdivision of the Chemung period in American geology. See Chart of Geology. Origin: So called from the township of Portage in New York. Source: Websters Dictionary (01 Mar 1998) |
| portal | 1. A door or gate; hence, a way of entrance or exit, especially one that is grand and imposing. "Thick with sparkling orient gems The portal shone." (Milton) "From out the fiery portal of the east." (Shak) 2. The lesser gate, where there are two of different dimensions. Formerly, a small square corner in a room separated from the rest of the apartment by wainscoting, forming a short passage to another apartment. By analogy with the French portail, used by recent writers for the whole architectural composition which surrounds and includes the doorways and porches of a church. 3. <engineering> The space, at one end, between opposite trusses when these are terminated by inclined braces. 4. A prayer book or breviary; a portass. <engineering> Portal bracing, a combination of struts and ties which lie in the plane of the inclined braces at a portal, serving to transfer wind pressure from the upper parts of the trusses to an abutment or pier of the bridge. Origin: OF. Portal, F. Portail, LL. Portale, fr. L. Porta a gate. See Port a gate. <anatomy> Of or pertaining to a porta, especially the porta of the liver; as, the portal vein, which enters the liver at the porta, and divides into capillaries after the manner of an artery. Portal is applied to other veins which break up into capillaries; as, the renal portal veins in the frog. Source: Websters Dictionary (01 Mar 1998) |