The blood vessels supplying the liver can be divided ito two: the hepatic artery, which brings oxygen from the aorta, This oxygenated blood comes from the general circulation; and the hepatic portal vein, which brings blood that has been enriched with nutrients. In this way the liver receives a dual blood supply from the hepatic portal vein and hepatic arteries.
The hepatic portal vein carries venous blood drained from the gastrointestinal tract and supplies approximately 75% of the liver's blood. The pressure on the hepatic artery is much greater than for the hepatic vein. Both veins and arteries are involved in, and vital for, the blood supply to the liver.