1. Digestion I. Introduction A. Processes The basic digestive processes  Ingestion, Digestion (mechanical and chemical), Absorption (extra-cellular and intracellular), and Elimination. Figure 41.7

2. B. Parts Overview The basic parts  1. tube (alimentary canal, G-I tract, etc.) and 2. a series of glands (salivary, liver, pancreas, etc.) Figure 41.8

3. II. Development A. Simplest 1. Direct == Poriferans Figure 33.4 Choanocytes

4. 2. Gastrovascular cavity  Cnidarians through Platyhelminthes Figure 33.10Figure 41.7

5. B. Complex 1. Alimentary canal == Nemertea through the Chordates Figure 41.8 How is food moved through the tube? What forces are involved? Why have the segmentation of the tube?

6. III. Mammalian Strategy A. Tube 1. 1. Sections Figure 41.9

7. 2. 2. Functions a. Oral cavity = ingestion, chewing, & chemical digestion b. Pharynx = move & lubricating food c. Esophagus = move, lubricating food, & peristalsis d. Stomach = churn food & chemical digestion

8. e. Small Intestine = chemical digestion& absorption Figure 41.12 via surface area Figure 41.13

9. f. Large Intestine  water absorption & packing

10. g. Rectal and Anal Canals = packing & elimination muscular wall

11. B. Glands & Organs 1. Salivary Glands Secrete mucin, salivary amylase, buffers, & antimicrobial agents Saliva to coat food, start carbohydrate digestion, control acidity, and prevent infection

12. 2. Gastric Glands Secrete pepsinogen, HCl, & mucous. Figure 41.11 begin protein digestion, activate pepsinogen to pepsin, and buffer

13. 3. Liver & Gall Bladder secrete or store bile Figure 41.19 emulsifies fat

14. 4. Pancreas Pancreas = secrete numerous digestive enzymes Figure 41.12

15. C. Absorption 1. What are the molecules and the 2. mechanism of absorption for each of the ingested nutrient molecules?

16. D. Regulation 1. Cephalic A nervous response a. Events: Stimuli related to food Salivary secretions Stimulation of the stomach smooth muscle b. Outcomes:

17. 2. Gastric A nervous response and endocrine input a. Events: Stimuli is the stretching of the stomach wall? Release of stomach secretions Pancreatic enzymesLiver/GB bile release Smooth muscle stimulation b. Outcomes:

18. IV. Comparisons A. Dentition Adapted to accommodate different diets. Types of teeth = incisors, canines, premolars, & molars Figure 41.16

19. B. Tubular Divisions Adapted to accommodate different diets. Figure 41.17 Figure 41.18