Duodenum, Pancreas, and Abdominal Aorta LO3

3. Describe the relationships between the common bile duct, the pancreatic duct(s), and the duodenum.

Intrahepatic ducts variably conduct bile to either the left or right hepatic ducts, which are transmitted via the porta hepatis and unite to form the common hepatic duct. The common hepatic duct joins the cystic duct to form the (common) bile duct. Bile may thus drain from the common hepatic duct and move retrograde through the cystic duct for storage in the gallbladder. The (common) bile duct travels inferiorly, posterior to the duodenum, where it typically joins the pancreatic duct. The junction of the (common) bile duct and pancreatic duct is often dilated, a region known as the hepatopancreatic ampulla (of Vater). The hepatopancreatic ampulla drains through the major duodenal papilla into the descending (2nd) part of the duodenum. When present, the accessory pancreatic duct (which drains the superior portion of the head of the pancreas) enters the descending duodenum about 2 cm proximal to the major duodenal papilla. Variants exist with each duct draining independently into the duodenum. The entirety of this region is often called the pancreaticobiliary junction by clinicians.