1 / 66

Digestion

Digestion. Anatomy & Physiology II Tony Serino, Ph.D. Biology Department Misericordia University. Digestion. The reduction through mechanical and chemical means (hydrolysis) of complex food substances into simple monomers and their absorption into the internal environment.

azizi
Télécharger la présentation

Digestion

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Digestion Anatomy & Physiology II Tony Serino, Ph.D. Biology Department Misericordia University

  2. Digestion • The reduction through mechanical and chemical means (hydrolysis) of complex food substances into simple monomers and their absorption into the internal environment.

  3. Functions of Digestive System • Motility(Propulsion) • Ingestion –food enters tract • Mastication -chewing • Deglutition -swallowing • Transportation through tract (peristalsis) • Mixing • Egestion (Defecation) • Secretion • Endocrine and Exocrine secretions • Digestion • mechanical and chemical breakdown of food • Absorption • Passage of food particles from external to the internal environment

  4. Major Organs of System

  5. Teeth Accessory Organs

  6. GI Tract Development Post-gastrula Late Gastrulation Pylorus

  7. Basic Histology of Digestive Tract (Auerbach’s) (Meissner’s) (LOCI)

  8. Tube Movements Peristalsis Segmentation

  9. Retroperitoneal Position

  10. Peritoneal Cavity Lesser Peritoneal Cavity Greater Peritoneal Cavity

  11. Mesenteries

  12. Mesenteries

  13. Control of Overall GI Tract Activity

  14. Oral Cavity (sagittal) • Mucosa: Stratified Squamous epithelia • Muscularis: Skeletal muscle overlying bone • Functions: • Ingestion • Mastication • Hydration of food • Begins chemical digestion • Formation of bolus

  15. Oral Cavity (anterior) (Red Margin)

  16. Tongue Functions: mixing, speaking, and swallowing Intrinsic and extrinsic muscles Foliate papillae Three layers of skeletal muscle.

  17. Major Salivary Glands Secrete saliva –mixture of water, mucus, electrolytes, antibodies and enzymes. Enzyme is salivary amylase which breaks down starches.

  18. Teeth Function: mastication (chewing and grinding of foodinto a paste consistency)

  19. Primary Dentition

  20. Adult (Permanent) Dentition

  21. Tooth Anatomy Odontoblasts –secrete dentinAmeloblasts –secrete enamel

  22. Pharynx Function: deglutitionMucosa: Str. SquamousMuscularis: Skeletal

  23. Esophagus • Function: Deglutition • Two sphincters: upper and lower esophageal sphincters (lower is physiological only) • Retropleural position (therefore, covered by adventitia) • Mucosa: stratified squamous with many mucus glands (esophageal glands) • Muscularis: changes from skeletal to smooth muscle

  24. Esophagus Histology

  25. Deglutition (Swallowing)

  26. Deglutition (cont’d)

  27. Stomach (cadaver) • J-shaped muscular pouch • Receives bolus and produces chyme • Liquefies food by mixing it with HCl and vigorous churning • Low pH stops amylase activity, but secretes pepsinogen (pepsin) that begins break down of proteins • Absorbs little except imbibed water, electrolytes, and some drugs (ie. alcohol and aspirin)

  28. Stomach Anatomy • Mucosa: • simple columnar folded into rugae • No villi • Openings leading to gastric pits and glands • Muscularis: • Has three layers

  29. Rugae of Stomach Temporary longitudinal foldings of the mucosa

  30. Stomach Histology

  31. Gastric Gland

  32. Regulation of Gastric Juice

  33. Gastric Emptying

  34. Gastric Emptying

  35. Inhibition of Gastric Emptying

  36. Small Intestine

  37. Small Intestine

  38. Duodenum and Accessory Organs

  39. Small Intestine Structures to Increase Surface Area Plica Circularis Villi Long Length of SI

  40. Small Intestine Histology

  41. Histology Changes in Intestine

  42. Villi Histology

  43. Large Intestine (x-ray)

  44. Large Intestine (Colon)

  45. Large Intestine Histology

  46. Anal Canal

  47. Defecation Reflex

  48. Upper Abdominal XS

  49. Liver

  50. Liver (inferior surface)

More Related