Portal vein

Portal vein
The portal vein (in light blue) and its tributaries. It is formed by the superior mesenteric vein, inferior mesenteric vein, and splenic vein. Lienal vein is an old term for splenic vein.
Details
System	Hepatic portal system
Drains from	Gastrointestinal tract, spleen, pancreas
Source	Splenic vein, superior mesenteric vein, inferior mesenteric vein, pancreatic vein
Drains to	Liver sinusoid
Identifiers
Latin	vena portae hepatis
MeSH	D011169
TA98	A12.3.12.001
TA2	5092
FMA	50735
Anatomical terminology [edit on Wikidata]

The portal vein or hepatic portal vein (HPV) is a blood vessel that carries blood from the gastrointestinal tract, gallbladder, pancreas and spleen to the liver. This blood contains nutrients and toxins extracted from digested contents. Approximately 75% of total liver blood flow is through the portal vein, with the remainder coming from the hepatic artery proper. The blood leaves the liver to the heart in the hepatic veins.

The portal vein is not a true vein, because it conducts blood to capillary beds in the liver and not directly to the heart. It is a major component of the hepatic portal system, one of three portal venous systems in the human body; the others being the hypophyseal and renal portal systems.

The portal vein is usually formed by the confluence of the superior mesenteric, splenic veins, inferior mesenteric, left, right gastric veins and the pancreatic vein.

Conditions involving the portal vein cause considerable illness and death. An important example of such a condition is elevated blood pressure in the portal vein. This condition, called portal hypertension, is a major complication of cirrhosis. In abdominal obesity fats, inflammatory cytokines and other toxic substances are transported by the portal vein from visceral fat into the liver, leading to hepatic insulin resistance and non-alcoholic fatty liver disease.^[1][2]