2. GIT hormones are CCK Secretin VIP Somatostatin Motilin Glucagon Entero-glucagon Neurotensin GRP Villikinin Gastrin

3. 1-Site of release: G- cells in the antral part of gastric mucosa and duodenal mucosa

4. Gastrin 34 34 amino acid Big gastrin Secrete during the interdigestive period (between meals) Secreted at low basal levels Types

5. Stimulus for release:  gastric distension  chemical factors (secretagogues) e.g. amino acid, coffee, alcohol, vegetables.  vagal stimulation (bombesin)

6. Gastrin Actions: Stomach: ++ secretions (HCL) ++ pyloric pump trophic factor to the mucosa Small intestine: ++ motility Pancreas: ++ secretions (enzymes)

7. Site of release: Mucosa of the upper small intestine (jejunum) Stimulus:  digestive products of fats and proteins (+ve feedback)  less by acids Cholecystokinin (pancreozymin)

8. synthesized as a pre-prohormone It has 2 types of receptors: 1)CCK A in the pancreatic acinar cell 2)CCK B in brain and stomach

9. 3- Actions: Pancreas : * ++ secretions ( rich in enzymes by action on pancreatic acini ) * augment secretin * stimulates glucagon secretion Stimulate pancreatic growth Gall bladder : ++ evacuation (cholagogue) Small intestine: ++ secretions & motility Stomach: -- secretions (HCL) & motility Cholecystokinin (pancreozymin)

11. Secretin Site of release: Mucosa of the upper small intestine as prosecretin and activated by acid into secretin Stimulus:  acid chyme (-ve feedback)

12. Actions: Pancreas: * ++ secretions (copious and very alkaline by action on pancreatic ducts) * augment CCK Biliary : ++ bile rich in H 2 O+HCO 3 (choleretic Stomach: -- secretions & motility Small intestine: ++ secretions but -- motility Secretin

14. Vaso-active intestinal peptide (VIP) Site of release: Glands and neurons throughout the intestine Stimulus:  neural stimulation  distension  Acid chyme

15. Actions: Pancreas: * ++ secretions (copious and alkaline by action on pancreatic ducts) Stomach: -- secretions & relax smooth muscles & stimulating pepsinogen secretion by chief cells Small intestine: ++ secretions but relax smooth muscles Blood vessels: vasodilatation Vaso-active intestinal peptide (VIP)

16. Somatostatin Growth Hormone Inhibiting Hormone (GHIH) or Somatotropin Release-Inhibiting Factor Site of release: D- cells in pancreas, GIT mucosa and hypothalamus Stimulus:  according to site of release

17. Actions: Stomach: -- secretions & motility Small intestine: -- secretions & motility Pancreas: -- secretions Gall bladder: -- evacuation _ Somatostatin

18. Site of release: M cells in small intestine(duodenum and jejunum)duodenumjejunum Stimulus Unknown, although some studies suggest that an alkaline pH in the duodenum stimulates its release Motilin Actions: 1-increases the migratory motor complex

19. villikinin Local hormone released by intestinal mucosa stimulus: digestive products of food. Action: it stimulates movements of villi and help absorption.