Bile Duct, Common

an effluent duct of the liver in vertebrates and man, formed by the union of the hepatic duct and the cystic duct.

The common bile duct opens into the lumen of the duodenum (in lower vertebrates, into the upper section of the midgut), usually together with the effluent duct of the pancreas. The wall of the bile duct contains muscle fibers forming Oddi’s sphincter, which regulates the periodic entry of bile into the intestinal tract.