Major Gastrointestinal Hormones

· Gastrin – secreted by G cell of antrum of stomach.

· Cholecytokinin – secreted by I cell of duodenum and jejunum. It strongly contracting gallbladder, expelling bile into small intestine where bile in turn plays important play important role in emulsifying fatty substances. It also inhibit stomach contraction moderately

· Secretin – secreted by S cell in response to acidic gastric juice emptying into duodenum. It has mild effect on motility of GIT and act to promote pancreatic secretion of bicarbonate

· Gastric Inhibitory Peptide – in response in fatty acid and amino acid. It has mild effect in decreasing motor activity of stomach and therefore slows emptying of gastric contents into duodenum

· Motilin – Increase gastrointestinal motility

· Somatostin – Inhibition of secretion of gastrin, VIP, GIP, secretin and motilin.