The liver has a dual blood supply; there are two blood vessels into the liver and one blood vessel out of the liver. The inlet vessels are the hepatic proper artery and the hepatic portal vein, and the outlet vessel is the hepatic vein. Blood to the liver is supplied by the hepatic proper artery and the hepatic portal vein. The innominate hepatic artery supplies the oxygen and nutrients needed for the liver’s own metabolism, while the hepatic portal vein accounts for 70% to 80% of the blood supply, and mainly transports water and nutrients absorbed from the intestinal tract into the liver to fulfill metabolic functions. The hepatic vein collects the nutrient-rich venous blood in the liver and converges to form the left hepatic vein, the middle hepatic vein and the right hepatic vein, which are injected into the inferior vena cava at the vena cava sulcus to carry out the return flow of blood further. The liver supplies oxygen and nutrients through the hepatic artery and the hepatic portal vein. After the supply of nutrients, the blood is detoxified and circulated in the liver, and then collected by the hepatic veins and converged to be injected into the inferior vena cava for further blood circulation.