portal circulation

circulation /cir·cu·la·tion/ (ser″ku-la´shun) movement in a regular course, as the movement of blood through the heart and blood vessels.

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collateral circulation  that carried on through secondary channels after obstruction of the principal channel supplying the part.

enterohepatic circulation  the cycle in which bile salts and other substances excreted by the liver are absorbed by the intestinal mucosa and returned to the liver via the portal circulation.

extracorporeal circulation  circulation of blood outside the body, as through an artificial kidney or a heart-lung apparatus.

fetal circulation  that propelled by the fetal heart through the fetus, umbilical cord, and placental villi.

Schematic diagram of fetal circulation, with red indicating the highest level of oxygen saturation, blue the lowest, and purple an intermediate level.

first circulation  primordial c.

hypophysioportal circulation  that passing from the capillaries of the median eminence of the hypothalamus into the portal vessels to the sinusoids of the adenohypophysis.

intervillous circulation  the flow of maternal blood through the intervillous space of the placenta.

lesser circulation  pulmonary c.

omphalomesenteric circulation  vitelline c.

persistent fetal circulation  pulmonary hypertension in the postnatal period secondary to right-to-left shunting of the blood through the foramen ovale and ductus arteriosus.

placental circulation 

1. the circulation of blood through the placenta during prenatal life.

2. intervillous c.

portal circulation  a general term denoting the circulation of blood through larger vessels from the capillaries of one organ to those of another; applied to the passage of blood from the gastrointestinal tract and spleen through the portal vein to the liver.

primordial circulation  the earliest circulation by which nutrient material and oxygen are conveyed to the embryo.

pulmonary circulation  the flow of blood from the right ventricle through the pulmonary artery to the lungs, where carbon dioxide is exchanged for oxygen, and back through the pulmonary vein to the left atrium.

systemic circulation  the general circulation, carrying oxygenated blood from the left ventricle to the body tissues, and returning venous blood to the right atrium.

umbilical circulation  fetal circulation through the umbilical vessels.

vitelline circulation  the circulation through the blood vessels of the yolk sac.

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portal circulation

n.

Circulation of blood to the liver from the small intestine via the portal vein.

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portal circulation

Etymology: L, porta, gateway, circulare, to go around

the pathway of blood flow from the GI tract and spleen to the liver via the portal vein and its tributaries. Also called hepatic portal circulation.

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circulation

movement in a regular or circuitous course, returning to the point of origin, as the circulation of the blood through the heart and blood vessels. See also circulatory system.

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antegrade circulation

circulation in the normal direction of flow.

artificial circulation

is maintained in cardiopulmonary arrest by cardiac compression.

collateral circulation

circulation carried on through secondary channels after obstruction of the principal channel supplying the part.

coronary circulation

that within the coronary vessels, which supply the muscle of the heart.

cutaneous circulation

cutaneous vessels are innervated by sympathetic adrenergic vasoconstrictor fibers; vasodilation is an important mechanism for losing heat after the body has been warmed.

enterohepatic circulation

the cycle in which bile salts and other substances excreted by the liver in the bile are absorbed by the intestinal mucosa and returned to the liver via the portal circulation.

extracorporeal circulation

circulation of blood outside the body, as through a hemodialyzer or an extracorporeal circulatory support unit.

fetal circulation

circulation of blood through the body of the fetus and to and from the placenta through the umbilical cord. See also fetal circulation.

hepatic circulation

includes the hepatic arterial blood supply and the supply from the portal vein; drainage is via the hepatic veins to the caudal vena cava.

lymph circulation

see lymph.

maternal circulation

the circulation of the dam during pregnancy, including especially that of the uterus.

micro-circulation

see microcirculation.

neonatal circulation

circulation in the newborn immediately after birth; the umbilical vessels contract forcing blood into the fetal veins; the foramen ovale closes, the ductus arteriosus narrows and eventually closes at day 1 to 2 after birth.

ocular circulation

consists of the uveal and retinal blood vessels supported by the aqueous humor and vitreous body.

placental circulation

consists of the umbilical arteries, the vessels of the placenta proper and the umbilical veins; approximates the fetal corporeal circulation in volume.

portal circulation

a general term denoting the circulation of blood through larger vessels from the capillaries of one organ to those of another; applied especially to the passage of blood from the gastrointestinal tract, pancreas and spleen through the portal vein to the liver.

pulmonary circulation

the flow of blood from the right ventricle through the pulmonary artery to the lungs, where carbon dioxide is exchanged for oxygen, and back through the pulmonary vein to the left atrium. See also pulmonary circulation.

splenic circulation

flow of blood through the splenic artery and arterioles to either the capillaries, e. g. white pulp, or the highly permeable sinuses of the red pulp. Splenic venous blood drains into the portal vein and passes through the liver before re-entering the general circulation.

systemic circulation

the flow of blood from the left ventricle through the aorta, carrying oxygen and nutrient material to all the tissues of the body, and returning through the superior and inferior venae cavae to the right atrium.

circulation time

the time required for blood to flow between two given points. It is determined by injecting a substance into a vein and then measuring the time required for it to reach a specific site.

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portal

1. an avenue of entrance; porta.

2. pertaining to an entrance, especially the porta hepatis.

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portal-azygos anastomosis

a form of portacaval shunt with the portal vein bypassing the liver and emptying directly into the azygos vein.

portal biliary bacterial circulation

a continuous normal circulation of bacteria brought to the liver in the portal vein from the gut and excreted back into the gut via the biliary system.

portal canal

tissue space situated between three or more hepatic lobules; carries the blood and lymphatic vessels and connective tissue.

portal-caval

see portacaval.

portal circulation

circulation of blood from the capillaries of one organ to those of another; applied especially to the passage of blood from the gastrointestinal tract and spleen through the portal vein to the liver. See also circulatory system.

portal of entry

the pathway by which bacteria or other pathogenic agents gain entry to the body.

portal fibrosis

see biliary fibrosis.

portal hypertension

see portal obstruction.

portal obstruction

obstruction of portal venous blood flow through external pressure on the portal vein, by abscess or tumor or by hepatic fibrosis constricting the hepatic vascular bed, causes interference with digestion and absorption and eventually venous return so that ascites and diarrhea develop.

portal system

an arrangement by which blood collected from one set of capillaries passes through a large vessel or vessels and another set of capillaries before returning to the systemic circulation, as in the pituitary gland and liver.

Includes the hepatic portal system consisting of portal vein and its tributaries from the stomach, intestine, pancreas and spleen, the vessels into which the portal vein divides in the liver and the hepatic veins that enter into the caudal vena cava.

portal systemic shunt

see portacaval shunt.

portal triad

anatomically close association of interlobular bile duct, branches of hepatic artery and portal vein.

portal vascular anomalies

see portacaval anastomosis.

portal vein

a short, thick trunk formed by the union of the caudal mesenteric and splenic veins; at the porta hepatis, it divides into successively smaller branches, following branches of the hepatic artery, until it forms a capillary system of sinusoids that permeates the entire substance of the liver.

portal vein obstruction

acute, complete obstruction causes a syndrome similar to that of intestinal obstruction without signs suggesting liver involvement; partial occlusion causes shrinkage and eventual atrophy of the relevant section of the liver.

portal vein rupture

rare complication of epiploic foraminal herniation; sudden death from internal hemorrhage results.

portal venule absence

a congenital defect resulting in the development of multiple shunts within the liver, hepatoportal fibrosis and ascites, general immaturity and hepatic encephalopathy.