Tag: endocrine system and chemical co-ordination

The pH of succus entericus is 7.8.

The correct answer is (d).

Cholecystokinin, previously called pancreozymin, is synthesized by I-cells in the mucosal epithelium of the small intestine and secreted in the duodenum. It is responsible for stimulating the digestion of fat and protein. Secretin is a peptide hormone that regulates water homeostasis throughout the body, and influences the environment of the duodenum by regulating secretions in the stomach and pancreas. Secretin is produced in the S cells of the duodenum, which are located in the crypts of Lieberkuhn.

Cholecystokinin (CCK), formerly called pancreozymin, is a digestive hormone released with secretin, when food from the stomach reaches the duodenum. Cholecystokinin causes contraction of the gallbladder, which forces bile into the duodenum.

Secretin stimulates the release of a watery bicarbonate solution from the pancreatic and bile duct epithelium. Secretin increases water and bicarbonate secretion from duodenal Brunner's glands to buffer the incoming protons of the acidic chyme. It also enhances the effects of cholecystokinin to induce the secretion of digestive enzymes and bile from pancreas and gallbladder, respectively.