1. Functions of the Digestive System

2. INGESTION
Food placed in mouth
Active, voluntary action

3. PROPULSION Food is propelled from one digestive to the next
Peristalsis (involuntary)
Alternating waves of contraction and relaxation of muscles in organ wall
Segmentation- single segments of intestine alternately contract and relax

5. FOOD BREAKDOWN Mechanical digestion- physical processes
Mixing of food in mouth by tongue, churning of food in stomach, segmentation in small intestine

6. FOOD BREAKDOWN Chemical Digestion
Large food molecules broken down to building blocks by enzymes

7. Chemical digestion
Proteins digested into polypeptides and peptides, then amino acids
Lipids(fats) digested into fatty acids and glycerol (Alcohol)

8. Carbohydrates We digest disaccharides and polysaccharides
Sucrose-table sugar
Lactose-milk sugar
Maltose- malt sugar
Starch

9. Carbohydrates Carbohydrate units are monosaccharides
Glucose- blood sugar
Fructose-fruits
Galactose-milk

10. Carbohydrates Cellulose is indigestible polysaccharide
Do not provide us with nutrients
Move digestion along by providing bulk in fiber to diet

11. ABSORPTION
Transport digested end products from lumen of GI tract to blood or lymph fluid
Digested foods must ender mucosal cells.
Small intestine is MAJOR ABSORPTIVE SITE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!

12. Defecation
Elimination of waste as feces