Secretin -

Ans. is 'b' i.e.. Reduces Gastric secretion Secretino Secretin is secreted by the S cells located in the duodenum and jejunum.o The most important stimulus for secretin secretion is the presence of acid in the duodenumQ.o Secretin secretion is also stimulated by the contact of products of protein digestion with the duodenal and jejunal mucosa.o Secretin acts through the group II-A hormonal mechanism, i.e., through cAMP as second messenger.o The following are the functions of secretin : -It stimulates the secretion of watery, alkaline (bicarbonate rich)6 pancreatic fluid that is poor in enzymes6.It potentiates the action of CCK on the pancreasQ;It increases the hepatic secretion of bileQ; i.e., it is a choleretic;It decreases gastric acid secretionQ;It increases the tone of pyloric sphinctorQ;It decreases rate of gastric emptyingQ;Secretin inhibits gastrin secretionQ.