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.

A short thick vein formed by union of the superior mesenteric vein and the splenic vein.

Veins which return blood from the intestines; the inferior mesenteric vein empties into the splenic vein, the superior mesenteric vein joins the splenic vein to form the portal vein.

Abnormal increase of resistance to blood flow within the hepatic PORTAL SYSTEM, frequently seen in LIVER CIRRHOSIS and conditions with obstruction of the PORTAL VEIN.

The venous pressure measured in the PORTAL VEIN.