1. The Digestive System

2. Digestion Processing of food Types Mechanical (physical) Chemical Chew
Tear
Grind
Mash
Mix
Chemical
Catabolic reactions
Enzymatic hydrolysis
Carbohydrate
Protein
Lipid

3. Digestion Phases Ingestion Movement Digestion Absorption
Further digestion

4. Digestive System Organization
Gastrointestinal (Gl) tract (Alimentary canal)
Direct link/path between organs
Structures
Mouth
Oral Cavity
Pharynx
Esophagus
Stomach
Duodenum
Jejunum
Ileum
Cecum
Ascending colon
Transverse colon

5. Digestive System Organization
Descending colon
Sigmoid colon
Rectum
Anus
Accessory structures
Not in tube path
Organs
Teeth
Tongue
Salivary glands
Liver
Gall bladder
Pancreas

6. Anatomy of the Mouth and Throat

7. Human Deciduous and Permanent Teeth

8. Dorsal Surface of the Tongue

9. The Major Salivary Glands

10. Deglutition (swallowing)
Sequence
Voluntary stage
Push food to back of mouth
Pharyngeal stage
Raise
Soft palate
Larynx + hyoid
Tongue to soft palate
Esophageal stage
Contract pharyngeal muscles
Open esophagus
Start peristalsis

11. Deglutition (swallowing)
Control
Nerves
Glossopharyngeal
Vagus
Accessory
Brain stem
Deglutition center
Medulla oblongata
Pons
Disorders
Dysphagia
Aphagia

12. Esophagus Usually collapsed (closed) Functions Secrete mucous
Transport food

13. Esophagus
Sphincters
Upper
Lower

14. Stomach Usually “J” shaped Left side, anterior to the spleen
Mucous membrane
G cells – make gastrin
Goblet cells – make mucous
Gastric pit – Oxyntic gland – Parietal cells – Make HCl
Chief cells – Zymogenic cells
Pepsin
Gastric lipase

15. Anatomy of the Stomach

16. Stomach 3 muscle layers Regions Vascular
Oblique
Circular
Longitudinal
Regions
Cardiac sphincter
Fundus
Antrum (pylorus)
Pyloric sphincter
Vascular
Inner surface thrown into folds – Rugae
Contains enzymes that work best at pH 1-2

17. Stomach Functions Absorbs Mix food Reservoir Start digestion of
Protein
Nucleic acids
Fats
Activates some enzymes
Destroy some bacteria
Absorbs
Alcohol
Water
Lipophilic acid

18. Small Intestine Extends from pyloric sphincter  ileocecal valve
Regions
Duodenum
Jejenum
Ileum
Movements
Segmentation
Peristalsis

19. Small Intestine Absorbs 80% ingested water Electrolytes Vitamins
Minerals
Lipids
Monoglycerides
Fatty acids

20. Structure of the Villi in the Small Intestine

21. Small Intestine Control
Requires pancreatic enzymes & bile to complete digestion

22. Large Intestine Extends from ileocecal valve to anus Regions
Cecum – Appendix
Colon
Ascending
Transverse
Descending
Rectum
Anal canal

23. Anatomy of the Large Intestine

24. Large Intestine Functions Mechanical digestion
Haustral churning
Peristalsis
Chemical digestion – Bacterial digestion
Ferment carbohydrates
Protein/amino acid breakdown
Absorbs
More water
Vitamins
Concentrate/eliminate wastes

25. Feces Formation and Defecation
Chyme dehydrated to form feces
Feces composition
Water
Inorganic salts
Epithelial cells
Bacteria
Byproducts of digestion
Defecation
Peristalsis pushes feces into rectum
Rectal walls stretch
Control
Parasympathetic
Voluntary

26. Liver Location 4 Lobes Each lobe has lobules – Contains hepatocytes
Left
Quadrate
Caudate
Right
Each lobe has lobules – Contains hepatocytes

27. Liver Functions Makes bile Detergent – emulsifies fats Contains Water
Salts
Pigments
Electrolytes
Cholesterol

28. Liver Detoxifies/removes Stores Activates vitamin D
Drugs
Alcohol
Stores
Glycogen
Vitamins (A, D, E, K)
Fe and other minerals
Cholesterol
Activates vitamin D
Fetal RBC production
Phagocytosis
Metabolizes absorbed food molecules
Carbohydrates
Proteins
Lipids

29. The Organs and Positions in the Abdominal Cavity