Gastrointestinal PhysiologySlide 2Slide 3Slide 4Important Disorders of the Gastrointestinal SystemThe digestive system performs six basic functionsSlide 7Slide 8Slide 9Slide 10Slide 11Morphology of GI epithelium is segment specific.GI physiology is regulated by three basic mechanismsSlide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Gastrointestinal Physiology•Dr. Hudson•121 Farber Hall•[email protected]•Office Hours and Location•The hour immediately following lecture in Diefendorf 147•By appointment: use email <[email protected]> and put PGY 451 in the subject line•Required Reading•Berne & Levy Physiology, 6th Edition•Chapters 26, 27, 28, 29, 30, 31The GI tract is a hollow tube that brings the outside world inside!Primary Function of the gastrointestinal (GI) system is to digest food and absorb nutrients, electrolytes (salts), and water into the body’s internal environment.Digestion is the process of breaking down ingested food into the basic components that can be absorbed. Absorption is the movement of these components, along with electrolytes and water, across the GI epithelium into the blood or lymph.The GI system includes not only the GI tract, but also accessory organs (salivary glands, liver gallbladder, and the exocrine pancreas). In addition are the enteric microorganisms/bacteria.OVERVIEWCecumAppendixDisturbances of normal GI function have a major impact, both on the health care system as well as lost economic productivity.In the US, approximately 300 million cases of gastrointestinal disorders at a cost of at least $100 billion dollars annually World wide, GI disorders are still a leading cause of morbidly and mortality.Important Disorders of the Gastrointestinal System35. Hemochromatosis36. Hemorrhoids37. Hepatitis38. Hepatic Cancer39. Hernia40. Hirschsprung’s Disease41. Indigestion42. Inflamatory Bowel Disease43. Inguinal Hernia44. Intestinal Pseudo-Obstruction45. Irritable Bowel Syndrome46. Islet Cell Carcinoma47. Jaundice48. Lactose49. Liver Cancer50. Liver Diseases51. Liver Transplantation52. Menetrier’s Disease53. Pancreas Transplantation54. Pancreatic Cancer55. Pancreatic Diseases56. Peptic Ulcer57. Porphyria58. Proctitis59. Pruritus Ani60. Rectal Disease61. Small Intestine Cancer62. Stomach Cancer63. Stomach Disorders64. Rapid Gastric Emptying65. Stomach Ulcer66. Swallowing Disorders67. Ulcerative Colitis68. Ulcers69. Virial Hepatitis70. Whipple’ Rectal Cancer71. s Disease72. Wilson’s Disease 1. Acid Reflux2. Anal Cancer3. Anal/Rectal Diseases4. Appendicitis5. Barrett’s Exophagus6. Bile Duct Cancer7. Celiac Disease8. Cholecystectomy9. Cirrhosis10. Colitis11. Colon Cancer12. Colon Polyps13. Colonic Diseases14. Constipation15. Crohn’s Disease16. Cyclic Vomiting Syndrome17. Delayed Gastric Emptying18. Diarrhea19. Digestive Diseases20. Diverticulosis21. Duodenal Ulcer22. Dysentery23. Dysphagis24. Esophageal Cancer25. Fecal Incontinence26. Gall Bladder Diseases27. Gall Bladder Cancer28. Gallstones29. Gastric Cancer30. Gastroesophaegeal Reflux31. GI Bleeding32. GERD33. Heart Burn34. Helicobacter Pylori InfectionThe digestive system performs six basic functions1. Motility2. Secretion3. Digestion4. Absorption5. Excretion6. ProtectionGeneral anatomy of the GI system and its division into functional segments1. Duodenum2. Jejunum3. Ileum1. Ascending2. Transverse3. Descending4. Sigmoid5. RectumFigure 21-2bFigure 21-2cThe Stomach WallGeneral organization of the layers composing the wall of the GI tractFigure 21-2eMorphology of GI epithelium is segment specific.GI physiology is regulated by three basic mechanismsLocationGastrointestinal HormoneCell that produces HormoneStomach Gastrin GSomatostatin DDuodenum or jejunum Secretin SCholecystokinin (CCK) IGastric Inhibitory peptide (GIP)(also known as Glucose-dependent insulinotropic peptide)KMotilin MSomatostatin DPancreatic Islets Insulin betaGlucagon alphaPancreatic polypeptide PPSomatostatin DIleum or Colon Enteroglucagon LPeptide YY LNeurotensin NSomatostatin DExtrinsic innervation of the GI tract via parasympathetic (A) and sympathetic (B) subdivision of the autonomic nervous system.Enteric nervous system is located within the wall of the GI tract.More than 100 million neurons (more than either the spinal column or peripheral nervous system)Take Home Message1. Basic anatomy of the GI tract including accessory organs.2. How is the movement of material between segments restricted?3. How does the GI tract change its effective surface area?4. What are the six primary functions of the GI system?5. What are the three basic mechanisms for regulating GI physiology?6. What is meant by the enteric nervous system?7. How is the enteric nervous system