1. Digestive System
Chapter 14

2. Functions Ingestion Propulsion Food breakdown: mechanical
Peristalsis
Segmentation
Food breakdown: mechanical
Food breakdown: chemical
Absorption
Defecation

3. Oral Cavity Mechanical breakdown of food
Enzymatic digestion of starches due to saliva

4. Alimentary Canal

5. Stomach Three muscle layers allow for churning motion
Rugae allow for expansion
Gastric Pits
Gastric glands
Enteroendocrine cells which secrete hormones
Chief cells which secrete pepsinogen
Parietal cells which secrete H+ and Cl-
Once food leaves stomach it becomes chyme

6. Stomach

7. Small Intestine
Plicae Circularis increase surface area and funnel chyme through the small intestine
Villi are comprised of microvilli amd small number of goblet cells
Microvilli contain brush border enzymes in plasma membrane
Duodenal papilla allow pancreatic juice and bile to enter small intestine

9. Small Intestine Three sections Lacteal –lymphatic capillary
Duodenum –characterized by Brunner’s gland in submucosa
Jejunum –longest section, absence of glands and lymphatic tissue in submucosa
Ileum –characterized by presence of Peyer’s patches in submucosa
Lacteal –lymphatic capillary

10. Large Intestine Absorb water Numerous goblet cells Haustra
Appendix is found at the junction of Ileum and Cecum

11. Accessory Glands Salivary glands –salivary amylase
Pancreas –buffer as well as small amount of enzymes
Liver –filters blood, produces bile (emulsifies fats)
Gall Bladder stores bile

12. Homeostatic Imbalances
Peritonitis
Gall Stones
Pancreatitis
Hepatitis
Cirrhosis
Jaundiced

13. Process of Digestion
Oral Cavity to Anus

14. Process of Digestion
Begins before we eat: thought, sight, smell of food primes salivary glands and stomach
Oral Cavity – mechanical breakdown (deglutination)
Stomach – mechanical \ chemical breakdown
Gastrin –stimulates chief and parietal cells
Histamine –stimulates parietal cells

15. Process of digestion Segmentation and peristalsis
Small Intestine –chemical breakdown and absorption
Gastrin –stimulates gastric glands
Somatostatin –inhibits gastric glands
Secretin –stimulates pancreas, gall bladder, inhibits gastric glands
Cholecystokinin (CCK) –stimulates pancreas, gall bladder
Gastric Inhibitory Peptide (GIP) –inhibits gastric glands, stimulates insulin release

16. Large Intestine Absorption of vitamins, ions and water
Chyme becomes feces when delivered to rectum

17. Nutrition
Lipids
Protein
Vitamins
Minerals

18. Metabolism
Cellular Respiration
Glycolysis
Krebs Cycle

19. Metabolism

20. Metabolism and the Liver
Glycogen –stored energy
Glycogenesis
Glycogenolysis
Gluconeogenesis
Cholesterol
LDL –lipids used by cells
HDL –lipids filtered by liver (produced as waste)
Ratio of the two is what is important