The common bile duct appears above the white arrow, and branches into the cystic duct (lower) and hepatic duct (higher) at the left. The black arrow appears to the right of the pancreatic duct. Both the pancreatic duct and the common bile duct merge at the ampulla at the lower right. This anatomic configuration, present in most persons, makes pancreatitis from gallstones impacting in the ampulla of Vater possible.

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