Porta: From 1 Different Sources
n. the aperture in an organ through which its associated vessels pass. Such an opening occurs in the liver (porta hepatis).
Raised blood pressure in the PORTAL VEIN entering the LIVER. This results in increased pressure in the veins of the oesophagus and upper stomach and these grow in size to form varices – dilated tortuous veins. Sometimes these varices rupture, causing bleeding into the oesophagus. The raised pressure also causes ?uid to collect in the abdomen and form ASCITES. The commonest reason for portal hypertension is cirrhosis (?brosis) of the liver (see LIVER, DISEASES OF). THROMBOSIS in the portal vein may also be a cause. Treatment requires the cause to be tackled, but bleeding from ruptured vessels may be stopped by injecting a sclerosant or hardening solution into and around the veins. Sometimes a surgical shunt may be done to divert blood from the portal vein to another blood vessel.... portal hypertension
A vein or collection of veins which ?nish at both ends in a bed of capillary blood vessels. An important example is the hepatic portal system, comprising the portal vein and its tributaries. Blood from the stomach, pancreas, spleen and intestines drains into the veins that join up to comprise the portal vein into the liver, where it branches into sinusoids.... portal system
Requirement in benefit plans that allow benefit rights to be transferred without waiting periods for persons moving between plans, regions or countries.... portability
This is a type of circulatory bypass used when substances in blood or fluid need to be kept out of the general flow. A portal system begins in capillaries and ends in capillaries, and nothing leaves it undocumented. The hypothalamus sends hormones into the portal system between it and the pituitary, and the pituitary responds to it by secreting its own hormones, but dissolving the hypothalamus ones. Blood that leaves the intestinal tract, spleen, and pancreas (partially) goes into the liver’s portal system and does not leave that organ until it has been thoroughly screened and altered.... portal circulation
adj. (in radiography) referring to images obtained by the bedside of the patient using light-weight equipment, rather than in the radiography department. The quality of portable radiographs is usually limited due to compromises in the equipment design to keep it light and movable, which is necessary when patients cannot easily be moved (for example, on intensive therapy units).... portable
(portacaval shunt) 1. a surgical technique in which the hepatic portal vein is joined to the inferior vena cava. Blood draining from the abdominal viscera is thus diverted past the liver. It is no longer widely used in the treatment of *portal hypertension. 2. any of the natural communications between the branches of the hepatic portal vein in the liver and the inferior vena cava.... portacaval anastomosis
adj. 1. relating to the portal vein or system. 2. relating to a porta.... portal
an electronic image taken during radiotherapy treatment to verify the position of radiation beams.... portal image
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