GIT_Lect_a3.ppt
- 1. Dr Pradeep Kumar, Professor department of physiology, KGMU, Lucknow
- 2. Gastrointestinal tract pancreatic secretions :its function and regulation
- 3. Gland with both exocrine and endocrine functions Location: retro-peritoneum, 2nd lumbar vertebral level 15-25 cm long 60-100 g Extends in an oblique, transverse position Parts of pancreas: head, neck, body and tail
- 6. The pancreas acts as an exocrine gland by producing pancreatic juice which empties into the small intestine at hepato pancreatic ampulla The pancreas also acts as an endocrine gland to produce insulin.
- 7. It plays an important role: in digestion of lipids proteins and carbohydrates, in metabolism since it produces insulin and other hormones. in neutralizing the pH to become suitable for the action of the pancreatic digestive enzymes.
- 8. Cations: Na + , K + , Ca 2+ , Mg 2+ (pH approximately 8.0) Anions: HCO 3 − , Cl − , SO 4 2− , HPO 4 2− Digestive enzymes (95% of protein in juice) Exocrine cells –produce 1200 to 1500 ml pancreatic juice /day
- 9. Secretion of water and electrolytes Na, K – the same as in plasma Bicarbonate concentration – up to 5 times higher than in plasma
- 10. CO2 diffuses to the ductule cells from blood CO2 combines with H2O in presence of CA to form H2CO3 H2CO3 dissociate into HCO3 - and H+ . The HCO3 - is actively transported into the lumen.
- 11. The H+ formed are exchanged for Na+ ions by active transport through blood , which will diffuse or actively be transported to the lumen
- 12. The movement of HCO3 - and Na+ ions to the lumen causes an osmotic gradient causes water to move from blood to ductule cells of the pancreas producing eventually the HCO3 - solution
- 14. Secretion of pancreatic juice is stimulated by: Secretin: ◦ Occurs in response to duodenal pH < 4.5. ◦ Stimulates production of HC03 - by pancreas. ◦ Stimulates the liver to secrete HC03 - into the bile. CCK: ◦ Occurs in response to fat and protein content of chyme in duodenum. ◦ Stimulates the production of pancreatic enzymes. ◦ Enhances secretin. Relaxation of the sphincter of Oddi.
- 15. Mechanism of enzymes activation Proteolytic enzymes – secreted as inactive precursors trypsinogen trypsin enterokinase chymotrypsinogen procarboxypeptidase chymotrypsin carboxypeptidase
- 17. Pancreatic alpha amylase starches glycogen Disaccharides and trisaccharides
- 21. Summery of the pancreatic regulation acid chyme in duodenum ENDOCRINE CONTROL enteroendocrine cells stimulated increased secretion of bicarbonate ions increased secretin increased cholecystokinin increased secretion of enzymes NEURAL CONTROL psychic stimuli stretch of stomach increased parasympathetic impulses via vagus nerve increased pancreatic secretion
- 22. Acute pancreatitis (inflammation in pancreas) Major causes Gall stone • Alcohol Ingestion Minor causes Over secretion of Ach Hyper- triglyceridemia Ingestion of pesticides Scorpion toxins
- 23. Lippincott’s Illustrated Reviews: Physiology (2013) Medical Physiology, UPDATED SECOND EDITION (Walter F. Boron, MD, PhD) BERNE & LEVY, PHYSIOLOGY, SIXTH EDITION, UPDATED EDITION Ganong’s Review of Medical Physiology, T W E N T Y -F O U R T H E D I T I O N
- 25. a. Alkaline PH b. Enterokinase c. Bile salts d. Chloride ion
- 26. a. Alkaline PH b. Enterokinase c. Bile salts d. Chloride ion
- 29. a. Gastrin b. Bile salts c. Enterokinase d. Chloride ions
- 30. a. Gastrin b. Bile salts c. Enterokinase d. Chloride ions
- 31. a. Its pH is about 8 b. Has high HCO₃⁻ content c. It’s secretion is primarily under neural control d. Contains digestive enzymes
- 32. a. Its pH is about 8 b. Has high HCO₃⁻ content c. It’s secretion is primarily under neural control d. Contains digestive enzymes
- 33. a. Bile salts b. Trypsin c. Cl ⁻ ions d. Enterokinase
- 34. a. Bile salts b. Trypsin c. Cl ⁻ ions d. Enterokinase
- 35. a. 0.6 liter b. 1.5 liter c. 3 liter d. 2.5 liter
- 36. a. 0.6 liter b. 1.5 liter c. 3 liter d. 2.5 liter
- 37. a. Sympathetic stimulation inhibits pancreatic HCO₃⁻ secretion b. The cephalic phase accounts for about 20 % of secretion after meal c. Pancreatic HCO3 depresses further release of secretin d. Contains enzymes which digest polysaccharides to monosaccharides
- 38. a. Sympathetic stimulation inhibits pancreatic HCO₃⁻ secretion b. The cephalic phase accounts for about 20 % of secretion after meal c. Pancreatic HCO3 depresses further release of secretin d. Contains enzymes which digest polysaccharides to monosaccharides
- 39. a. Somatostatin b. Glucagon c. Acid in the duodenum d. Sympathetic stimulation.
- 40. a. Somatostatin b. Glucagon c. Acid in the duodenum d. Sympathetic stimulation.
- 41. a. Maldigestion b. Malabsorption c. Dehydration d. Alkalosis
- 42. a. Maldigestion b. Malabsorption c. Dehydration d. Alkalosis
- 43. Thank you