The gallbladder is a pear-shaped cystic pouch structure located behind the liver under the right rib cage and is used for concentrating and storing bile. The gallbladder is divided into four parts: base, body, neck, and duct, with the cervical cystic duct. In order to adapt to this phenomenon and maximize the physiological effect of bile, the flow of bile is different at each time. During the inter-digestive period, the body stores bile in the gallbladder and discharges it to the duodenum after eating, which requires the gallbladder to have the following physiological functions: storage of bile, concentration of bile, emptying function, and secretion This requires the gallbladder to have the following physiological functions: bile storage, bile concentration, emptying function and secretion function. Storage of bile: During the inter-digestive period, the sphincter of Oddi in the jugular abdomen contracts and bile is obstructed from discharging into the duodenum, while the gallbladder dilates and bile flows retrograde to the gallbladder through the cystic duct for storage. Second, concentrated bile: the daily secretion of bile from the liver is as much as 800~1500ml, while the capacity of the gallbladder of normal people is about 50ml, so so much bile must be concentrated before it can be stored in the small gallbladder. After bile enters the gallbladder, the water and electrolytes in it can be absorbed rapidly, and about 10% of lecithin is also absorbed, while the effective components in bile such as bile salts, bile pigments and some macromolecules are not absorbed, thus increasing the concentration by about 5~20 times. Emptying function: After eating, food will stimulate the duodenum to produce a hormone called cholecystokinin, which can make the gallbladder contract, while the sphincter of Oddi is diastolic, so that bile can be smoothly discharged into the duodenum along the cystic duct and common bile duct to participate in digestion. Fourth, the secretion function: the gallbladder mucosa can secrete 20ml of thick mucus every day to protect the bile duct mucosa from the erosion and digestion of concentrated bile, and also has the function of lubricating the bile duct, which is beneficial to the discharge of bile.