Anatomy and Embryology of the Intra- and Extrahepatic Biliary Tract

Bile is a secretion produced by the liver that aims to reach the second portion of the duodenum. To do so, it travels through a system of ducts, collectively called the biliary tract, and is stored in a saccular pear-shaped organ during digestion intervals: the gallbladder. The system of intrahepatic ducts culminates in a common hepatic duct, which, when united with a duct related to the gallbladder (the cystic duct), forms a duct of greater caliber, the common bile duct. Ultimately, the common bile duct joins the main pancreatic duct (of Wirsung), forming the hepatopancreatic ampulla and flowing into the major duodenal papilla (of Vater), in its second portion. Such is the simple trajectory traversed by the bile, which has properties related to the digestion of lipids. In this chapter, we will describe the embryological aspects of the biliary tract and the gallbladder, followed by the descriptive anatomy of both, mentioning, whenever relevant, the clinical and surgical significance of these structures.