The duodenum of the small intestine contains the ampulla of vater. The ampulla of vater is the opening of both the bile ducts and the pancreatic ducts. In the liver, there is production of bile and bile is stored in the gall bladder. In response to a full stomach (mediated by the hormone cholecystokinin), the gall bladder contracts and releases bile (along with pancreatic enzymes) through the ampulla of vater to the duodenum. This is to aid the digestion of carbohydrates, protein, and emulsification of fats.