The hepatic portal vein is a vein which arises from networks in the stomach, intestines, pancreas, and spleen; these vessels carry blood from these organs through the hepatic portal vein to the liver. There, the blood enters capillary-like hepatic sinusoids, called the hepatic portal system. After passing through the portal veins of the liver, blood is carried through a series of merging vessels into the hepatic veins. These empty into the inferior vena cava, and return the blood into circulation.