1. Lab 8
Digestion

2. Lab 8: Digestion Histology Models of the digestive system
Parotid gland, esophagus, stomach, duodenum, jejunum, ileum, colon, liver, pancreas
Alimentary canal histological layers
Models of the digestive system
PhysioEx: Chemical and Physical Processes of Digestion
Learn to understand and interpret data tables + simulated test tube results for salivary amylase
Learn about the major digestive enzymes and their substrates
Examine the effect of heating, cooling, and pH on enzyme activity
Use indicators of enzyme activity (IKI, Benedict’s, etc.)

3. General Structure Digestive organs divided into 2 main groups
GI (alimentary) tract
Accessory structures
cheeks, teeth, tongue, salivary glands
liver, gallbladder, pancreas

4. General Organization of GI Tract

5. Histology of the GI Tract
#55: salivary glands
#56: esophagus
#57: stomach
#58: small intestine – duodenum
#59: small intestine - jejunum
#60: small intestine – ileum
#54: liver
#39: pancreas
#61: large intestine

6. Salivary Glands MA = mucous acinus; SA = serous acinus;
ducts lined by simple cuboidal epithelium

7. Parotid Salivary Gland

8. Esophagus

9. Esophagus

10. Esophagus – 4 tissue layers

11. Esophagus

12. Esophagus

13. Transition Zone
Simple columnar
Stratified squamous

14. Stomach

15. The interior wall of the stomach consists of a series of folds, called rugae.

16. Detail of Rugae

17. Fundus: gastric glands

18. Gastric Glands

19. G Cells produce Gastrin

20. Duodenum

21. Duodenum

22. Villi (multicellular)

23. Duodenum

24. Villi and Intestinal Crypts

25. Duodenum

26. Jejunum

27. Jejunum

28. Ileum with MALT = Mucosal Associated Lymphatic Tissue

29. Ileum

30. Ileum with Peyer’s Patches = aggregated lymphatic nodules

31. Ileum and Plicae Circularies
Lacteal

32. Liver in cross section

34. Liver Lobules

35. Liver Parenchyma

36. Hepatocytes

37. Liver Lobule

38. Pancreas

39. Pancreas
Exocrine: acinar cells
Endocrine: islet cells

41. Pancreas
Acinar Cells

42. Large Intestine (Colon)

43. Appendix

44. Appendix

45. Colon

46. Colon

47. Glands in Colon

48. Glands in Colon
colon polyp

49. Experiment 1: Starch Digestion
PhysioEx 39B
Experiment 1: Starch Digestion

50. Starch Digestion by Amylase
Starch is a polymer composed of repeating units of glucose.
Amylase breaks starch into smaller subunits such as maltose.
Maltose

52. Load 7 tubes

53. Fill 7 tubes,
use droppers

54. Boil tube 1,
Incubate tubes

55. Transfer liquid
to new tubes

56. Add IKI reagent
Add Benedict’s reagent and incubate

57. Print data table and answer questions as directed in your Lab manual
Record data
Print data table and answer questions as directed in your Lab manual

58. End Lab 8
Please bring a full bladder to lab next week for urinalysis!