The liver has a dual blood supply. The portal vein (which is rich in nutrients and relatively high in O2) provides two thirds of blood flow to the liver. The hepatic artery (which is O2-rich) supplies the rest. The hepatic veins drain the liver into the inferior vena cava. When portal vein blood flow increases, hepatic artery flow decreases and vice versa (the hepatic arterial buffer response). This dual, reciprocally compensatory blood supply provides some protection from hepatic ischemia in healthy people.
Despite its dual blood supply, the liver, a metabolically active organ, can be injured by
Last full review/revision December 2007 by Eldon A. Shaffer, MD
Content last modified February 2012