<prompt> Cholecystokinin is produced from:HepatocyteGastric mucosaDuodenal mucosaEpithelial cells of distal common bile duct  <response>: The major factor controlling the contraction of the gallbladder is the hormone cholecystokinin CCK, which is released from the duodenal mucosa I cells in response to the ingestion of fats and amino acids. REF: GUYTON 12TH ED. 