A group of veins which have capillaries at both ends and do not go to the heart.
A vein or group of veins that terminates at both ends in a capillary bed. The best known is the hepatic portal system, which consists of the portal vein and its tributaries. Blood is drained from the spleen, stomach, pancreas, and small and large intestines into veins that merge to form the portal vein leading to the liver. Here the portal vein branches, ending in many small capillaries called sinusoids. These permit the passage into the liver cells of nutrients absorbed by blood from the intestines.
A vein or collection of veins finishing 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.
A system of vessels in which blood passes through a capillary network, a large vessel, and then another capillary network before returning to the systemic circulation (e.g., the circulation of blood through the liver).