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 Choanocytes
Figure 33.4

4. 2. Gastrovascular cavity  Cnidarians through Platyhelminthes
Figure 33.10
Figure 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. Sections
Figure 41.9

7. 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 emulsifies fat
Figure 41.20

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

15. C. Absorption 1. What are the molecules
2. Mechanism/Pathways of absorption

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

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

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 41.19