Master Cholecystokinin (CCK) with Picmonic for Medicine

CCK is secreted by I cells, which are located in the duodenum and jejunum.

One of the actions of CCK is to increase secretion of pancreatic juices into the GI tract. These juices contain various enzymes that aid in the breakdown of ingested food.

CCK induces gallbladder contraction, which promotes emptying of bile into the GI tract and aids in digestion.

CCK acts to release the sphincter of Oddi, which is the sphincter that controls the opening of the common bile duct into the duodenum. Relaxation of the sphincter of Oddi allows emtpying of pancreatic and gallbladder secretions into the intestine, allowing them to aid in digestion.

CCK reduces gastric emptying by multiple mechanisms, one of which is stimulating vagal afferent nerve fibers, causing a feedback mechanism that slows gastric emptying and induces satiety.

Ingestion of amino and fatty acids in meals stimulates secretion of CCK, which in turn stimulates secretion of various digestive enzymes by the pancreas and gallbladder to aid in the breakdown of the very same amino and fatty acids.