The gallbladder is one of the important digestive organs, and the gallbladder and the bile duct together constitute the biliary system. 1.Gallbladder: The gallbladder is located in the gallbladder fossa below the liver, and some of its locations are deeper, even buried in the liver parenchyma. While most of the liver is located in the right quadrant and the supra-abdominal area, a small part is located in the left quadrant. The gallbladder is connected to the liver above and adjacent to the gastric sinus and duodenal bulb below. The triangular area enclosed by the cystic duct, common hepatic duct and the dirty surface of the liver is called the gallbladder triangle. The gallbladder triangle often has the gallbladder artery passing through it, and the triangle is a marker for finding the gallbladder artery during gallbladder surgery. 2.Biliary system: The biliary tract is mainly divided into intrahepatic bile duct and extrahepatic bile duct. The intrahepatic bile duct starts from the capillary bile duct. The extrahepatic bile ducts are divided into the right and left hepatic ducts, the common hepatic duct and the common bile duct. 3.Physiological functions: (1) Bile production, secretion and metabolism. Adults secrete about 800-1200ml of bile daily, which is mainly secreted by hepatocytes. It mainly has the physiological functions of emulsifying fat, neutralizing stomach acid and stimulating intestinal peristalsis. (2) Physiological functions of bile ducts. The main physiological function of the bile duct is to transport bile to the gallbladder and duodenum, which is coordinated by the gallbladder and the sphincter of Oddi. (3) Physiological functions of the gallbladder. It is mainly the function of concentrating and storing bile, excreting bile and secretion.