When common hepatic duct (left and right hepatic ducts) joins the cystic duct of gall bladder, the formation of bile duct or common bile duct takes place. This bile duct downward posteriorly joins the main pancreatic duct to form the hepatopancreatic duct. Pancreas is a mixed gland. Its exocrine part secretes pancreatic juices, while insulin and glucagon are secreted by the endocrine parts