1. Anatomy & Physiology II
Unit Three

2. Digestion
The digestive tract is a tubular passage that extends from the lips of the mouth, through the body, and terminates with an anus
This system can be divided into three regions:
+ oral cavity
+ pharynx
+ alimentary canal

3. Digestion
The alimentary canal can be further divided into four segments:
+ esophagus
+ stomach
+ small intestine
+ large intestine

4. Digestion
Associated with the system are four glands/organs that are located outside the tube, but secrete fluids into the system to aid in digestion:
+ salivary glands
+ liver
+ gall bladder
+ pancreas

5. Digestive System

6. Digestion
The function of the digestive system is to mechanically & chemically breakdown food so that nutrients can be obtained through absorption and energy can be released

7. Digestion
Mechanical digestion breaks the food into physically smaller particles, while chemical digestion breaks macromolecules into monomers

8. Digestion
The monomers and other nutrients are now small enough to be absorbed through the wall of the digestive tract and into the bloodstream where they will be distributed to body cells for energy needs and building materials

9. Oral Digestion Oral structures involved in mechanical digestion:
Hard palate
Uvula
Oral structures involved in mechanical digestion:
* teeth
* tongue
* hard palate
* cheeks
Tonsil
Soft palate
Tongue
Teeth

10. Oral Digestion Enamel Dentin Canines Incisors Pulp Gingiva Molars
Premolars

11. Oral Digestion Oral structures involved in chemical digestion:
* parotid salivary
glands
* submandibular
salivary glands
* sublingual
Parotid salivary gland
Submandibular salivary gland
Sublingual salivary gland

12. Oral Digestion Structures involved in swallowing: * soft palate &
Uvula
Hard palate
Structures involved in swallowing:
* soft palate &
uvula
* pharynx
* epiglottis
* esophagus
Pharynx
Tonsils
Epiglottis
Glottis
Esophagus

13. Oral Digestion
Deglutition (swallowing)

14. Alimentary Canal Histology
Serosa
Mucosa
Submucosa
Muscularis externa (longitudinal muscle)
Muscularis interna (circular muscle)

15. Alimentary Canal Movements
Segmentation
Peristalsis

16. Alimentary Canal Movements

17. Alimentary Canal
Esophagus
Diaphragm
Stomach

18. Stomach Diaphragm Esophagus Fundic region Cardiac region Body
A aa
Lesser curvature
Muscle layers
Rugae
Pyloric antrum
Greater curvature
Pyloric sphincter

19. Stomach Wall Rugae Gastric pit Mucosa Gastric gland Submucosa
Muscularis
layers
Serosa

20. Cardiac or Pyloric Gland
Stomach Wall
Cardiac or Pyloric Gland
Gastric Gland
Mucous cell
Parietal cell
Chief cell
G cell

21. Activation of Pepsin

22. Control of Gastric Secretion

23. Control of Gastric Secretion

24. Stomach Disorders
Emesis - the forceful ejection of stomach or duodenal contents
Bulimia – eating disorder in which emesis is induced so as to rid the body of the food recently eaten

25. Stomach Disorders
Anorexia – eating disorder in which a person loses their appetite because they believe they are fat
Peptic ulcers – erosion of the stomach lining caused by bacteria, aspirin, HCl or pepsin

26. Accessory Organ Anatomy
Liver
Common hepatic duct
Gall bladder
Anterior
Posterior

27. Liver Function The liver carries out a number of functions:
> degradation of toxins, drugs,
etc.
> cleaning bacteria and debris
from the blood
> produces and secretes plasma
proteins

28. Liver Function
The liver carries out a number of functions that concern digestion:
> process the monomers of
digestion
> processes vitamins and iron
> produces bile

29. Accessory Organ Anatomy

30. Liver Function
Cirrhosis of the liver is the replacing of liver tissue with connective tissue, reducing the function of the liver

31. Liver Function Cirrhosis can have several causes:
> viral (hepatitis)
> drug abuse
> trauma

32. Accessory Organ Anatomy
Gall bladder
Hepatic ducts
Common hepatic duct
Common bile duct
Cystic duct
Hepatopancreatic duct
Pancreatic duct
Pancreas
Hepatopancreatic sphincter
Duodenum

33. Small Intestine Anatomy

34. Small Intestine Physiology

35. Small Intestine Physiology
Villus
Microvilli
(brush border)
Capillaries
Lacteal

36. Small Intestine Physiology

37. Large Intestine Anatomy

38. Large Intestine Disorders
Diverticulitis
Diarrhea
Constipation
Flatulence