1. BIOL 204 Lab For Week 12 Digestive System Anatomy
                

2. Microscopic Anatomy of the GI Tract
The GI tract consists of a tube that extends from the mouth to the anus. It has four tissue layers (tunics):

3. Another, detailed view of GI tract tunics

4. There are structural modifications of the tunics in various areas of the GI tract

5. Gross Anatomy of the GI Tract

7. The GI Tract: Mouth

9. The Esophagus

10. The Esophagus

11. Gastroesophageal Junction
Gastric pit

12. The Esophagus

13. The Stomach

14. Microscopic anatomy of the stomach.

15. The Liver
Gross View of the Liver

16. The Duodenum of the Small Intestine Receives the Ducts of the Liver, Gall Bladder and Pancreas

17. Liver Microscopic Anatomy

18. Pancreas Gross Anatomy

19. Microscopic View of the Pancreas:
Islet Cells: endocrine; secrete insulin and glucagon
Acinar Cells: exocrine; secrete digestive enzymes

20. Small Intestine Gross Anatomy

21. Histology of the Small Intestine
(Duodenum)

22. Intestinal Villus

23. Portions of the Large Intestine

24. Extrinsic Salivary Glands

25. Types of Permanent Teeth
Each jaw has:
2 central incisors
2 lateral incisors
2 canines (eyeteeth)
4 premolars
6 molars

26. Internal Anatomy
of a Tooth

27. Mesenteries of the abdominal digestive organs.

28. Diaphragm
Liver – left lobe
Falciform Ligament
Liver right lobe
Stomach
Greater Omentum
Ascending Colon
Cecum
Small Intestine
Descending Colon
Sigmoid Colon

29. An Appendix, Unfixed

30. Gall Bladder on the Underside of the Liver

31. Liver – Gross View
Serosal Surface

32. Human Duodenum, Unfixed

33. Cat Dissection Parotid Gland Sublingual Gland Submandibular Gland
Esophagus
Tongue
Masseter Muscle
Larynx
Trachea
            
         
           
  1. Parotid gland
  2. Sublingual gland
  3. Submandibular gland
  4. Esophagus
  5. Tongue
  6. Masseter muscle
  7. Larynx
  8. Trachea

34. Cat Dissection Abdomen 1. Diaphragm 7. Right Medial Lobe of Liver
2. Round Ligament 8. Right Lateral Lobe of Liver
3. Falciform Ligament 9. Gall Bladder
4. Left Lateral Lobe of Liver 10. Spleen
5. Left Medial Lobe of Liver 11. Greater Omentum
6. Quadrate Lobe of Liver

35. Cat Abdomen – Greater Omentum Removed
1. Cardiac Stomach 8. Ascending Colon
2. Fundic Stomach 9. Ileum
3. Stomach Body 10. Jejunum
4. Pyloric Stomach 11. Sigmoid Colon
5. Lesser Omentum 12. Spleen
6. Duodenum 13. Gastrospleenic Ligament
7. Pancreas (Ventral) 14. Bladder

36. Small and Large Intestine Removed

37. 1. Small Intestine 6. Transverse Colon
2. THE Mesentary 7. Descending Colon
3. Ileum 8. Sigmoid Colon
4. Cecum 9. Mesocolon
5. Ascending Colon 10. Greater Omentum

38. Gall Bladder and Lobes of the Liver
                                                                                                                                                                                                                             

39. BIOL 204 Lab
Week 12
Digestive Enzymes

40. Digestive Enzymes:
are used in the lumen of the GI tract to break down complex molecules into absorbable subunits
Enzymes are biological catalysts which increase the rate of a chemical reaction without themselves becoming part of the product:

41. Amylase: digests starch into disaccharides
In this experiment we will observe the activity of three different enzymes:
Amylase: digests starch into disaccharides
Trypsin: digests proteins into peptides
Lipase: digests fats into glycerol and fatty acids

42. Variables tested ……
Incubation temperature:
How will enzyme activity compare when incubated at O o C and 37 o C?
Denaturization of Enzymes
How will enzyme activity be altered if the enzyme is denatured by boiling?

43. Activity 1 Trypsin Activity
Trypsin an enzyme, secreted by pancreatic acinar cells, that hydrolyzes proteins into small fragments (peptones, peptides and proteoses)”

44. What do you predict will happen?
In this experiment, trypsin will act on an artificial substrate to yield a yellow colored product:
Trypsin
BAPNA + H2O N-benzoyl-L-arginine + p-nitroaniline (yellow)
1. Reaction rate will be compared at these different incubation temperatures:
370 C and 0o C
What do you predict will happen?
2. The rate of the reaction will be determined using boiled trypsin. What do you predict will happen?

45. Starch + H2O maltose (disaccharides)
Activity Amylase Activity
Amylase is a carbohydrate digesting enzyme, produced by salivary glands and pancreatic acinar cells, that hydrolyzes starch into maltose (disaccharides):
Amylase
Starch + H2O maltose (disaccharides)

46. Indicators:
Starch: IKI (Lugol’s solution) - turns “blue/black” in the presence of starch
Benedict’s Solution: turns green/orange/ red/brown in the presence of reducing sugar

47. IKI Test For Starch in a Spot Plate
Benedict’s Test for reducing sugar in heat test tubes

48. As in activity one, the reaction will be observed under different conditions:
Boiled Enzyme (Amylase)
Incubation Temperature: 0oC and 37oC

49. Activity 3 Lipase Activity
Lipase is a hydrolytic enzyme, made primarily by pancreatic acinar cells, that hydrolyzes neutral fats into fatty acids and glycerol:
Lipase
Fat H2O Fatty Acids + Glycerol

50. Fat Digestion: Indicator:
Blue litmus turns pink (red) in the presence of acid (one the products is fatty acids)

51. Bile emulsifies fat….

52. incubation temperature (0oC vs. 37oC)
In this activity, you will examine the effect of:
incubation temperature (0oC vs. 37oC)
and
addition of bile salts
on the reaction