This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T., Subject name: Physiology
[{'content': 'Function of secretin is? \nSelect and explain. \nA. Relax pyloric sphincter, B. Increase gastric acid secretion, C. Increase gastric motility, D. Bicarbonate secretion from pancreas', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. D Bicarbonate secretion from pancreasRef: Quantitative Human Physiology; An Introduction, pg. 711-712Important differences between GIT hormones (Gastrin, CCK, Secretin, GIP) GastrinCCKSecretinGIPSiteMain site: G cells (antrum)I-cells of the proximal two- thirds of small intestineS-cells: Upper small intestineK-cells: Proximal intestinal cryptsActionsMajor:* Stimulate acid and pepsin secretion* Stimulate gastric motility* Act as growth factor to stimulate mucosal proliferationMajor:* Stimulate pancreatic acinar cell enzyme secretion* Stimulate GB contraction* Relaxes sphincter of oddi* Inhibits gastric acid secretion and gastric emptying* Pyloric sphincter contraction* Major: Secretion of HCO3 from biliary and pancreatic ductular cell and Brunner gland.* Inhibit gastric acid secretion* Stimulate pyloric sphincter* Increases bile flow* Augments the action of CCKMajor: Stimulate insulin release from pancreasMajor stimulusPeptides (most potent)Distension of stomach CalciumGRP (gastrin releasing peptides)Peptides (most potent)Fatty acid (BUT NOT TG)Acid (most potent)Digestive proteinGlucose, fat and amino acid', 'role': 'assistant'}]