Dave Heeransh D., Shumway Karlie R., Al Obaidi Nader M.
Tver State Medical University, Tver, Russian Federation
Henry Ford Health
The biliary system refers to bile production, storage, and secretion via the liver, gallbladder, and bile ducts. Bile ducts are categorized into intrahepatic and extrahepatic bile ducts (see Diagram of the Biliary System). Intrahepatic bile ducts include the left and right hepatic ducts, which join to form the common hepatic duct (CHD), while extrahepatic bile ducts include the common bile duct (CBD), which is formed from the CHD and cystic duct. The CBD and pancreatic duct converge to form the ampulla of Vater, which bile travels through before passing through the sphincter of Oddi and into the second portion of the duodenum. Initially, bile is a unique alkaline (7.5 to 8.1 pH) fluid secreted by hepatocytes (600-1000 mL/day), further altered and refined by the epithelial cells lining the biliary tract, and becoming acidic in the gallbladder (5.2 to 6.0 pH). The gallbladder stores this fluid, where it gets concentrated and subsequently released into the digestive tract via the CBD. After receiving stimulation via the hormone cholecystokinin (CCK) from the intestinal tract due to food in the intestinal lumen, the gallbladder contracts and secretes bile into the duodenum. Bile is predominantly water with multiple dissolved substances, including cholesterol, amino acids, enzymes, vitamins, heavy metals, bile salts, bilirubin, and phospholipids.
胆道系统是指通过肝脏、胆囊和胆管进行胆汁的生成、储存和分泌。胆管分为肝内胆管和肝外胆管（见图：胆道系统）。肝内胆管包括左、右肝管，它们汇合形成肝总管（CHD），而肝外胆管包括胆总管（CBD），它由肝总管和胆囊管汇合而成。胆总管和胰管汇合形成Vater壶腹，胆汁在通过Oddi括约肌进入十二指肠第二部之前先流经此处。最初，胆汁是由肝细胞分泌的一种独特的碱性（pH值为7.5至8.1）液体（每天600 - 1000毫升），经胆道内衬上皮细胞进一步改变和精制后，在胆囊中变为酸性（pH值为5.2至6.0）。胆囊储存这种液体，使其浓缩，随后通过胆总管释放到消化道。在肠道内的食物通过激素胆囊收缩素（CCK）刺激胆囊后，胆囊收缩并将胆汁分泌到十二指肠。胆汁主要是水，含有多种溶解物质，包括胆固醇、氨基酸、酶、维生素、重金属、胆汁盐、胆红素和磷脂。
