The liver is the largest organ in the body, with a mass of about 1.2-1.5 kg. It is hidden in the right upper abdomen, where it cannot be felt and is protected by the right rib cage, which is soft and has a smooth surface. Without the protection of the ribs, even minor external injuries may result in crushing and bleeding. Anatomically, the liver is divided into two lobes, the left and the right, with the right lobe being larger than the left. Unlike other organs of the body that receive arterial blood supply and venous outflow, the liver receives a dual blood supply from the hepatic artery and portal vein. The hepatic artery is rich in oxygen and the portal vein is rich in nutrients absorbed from the gastrointestinal tract. This unique blood supply system of the liver is related to the unique functional role of the liver. The absorbed nutrients are first processed, processed and stored in the liver, the chemical factory of the body. The blood flow through the hepatic artery is about 400 ml/min and through the portal vein is about 1200 ml/min, i.e. about 1/4 of the total blood flow to the liver through the hepatic artery and 3/4 of the total blood flow to the liver through the portal vein. The liver has the function of secreting and excreting bile, which is produced in the liver and drained out of the liver through the bile duct, then stored briefly in the gallbladder and excreted through the small intestine. The gallbladder is shaped like a pear, with a volume of about 50 ml, and is suspended from the lower edge of the right liver. The liver contains 250 billion hepatocytes, which are now confirmed to be capable of performing up to 500 chemical reactions in a short period of time. Strikingly, most of this amazing function is accomplished within a single hepatocyte with a diameter of only 15-30 μm (1/1000 mm for 1 μm). The hepatic artery and portal vein entering the liver gradually thin out and finally merge into the hepatic blood sinusoids. Here, oxygen and nutrients are supplied to the hepatocytes, while waste products such as carbon dioxide and various metabolites are removed from the body via the blood stream. The hepatic sinusoids finally merge into the central vein, and then numerous central veins collect to form the hepatic veins, which exit the liver into the heart.