2. Digestive System Chapter 14 Figure 14.1 Pharynx • Passageway for food and air • Participates in swallowing Esophagus • Moves food from pharynx to stomach Salivary glands • Saliva moistens food • Bicarbonate maintains pH • Amylase digests starch • Lysozyme inhibits bacteria ACCESSORY ORGANS: Liver • Produces bile • Performs various functions associated with processing and storing nutrients Pancreas • Secretes digestive enzymes into small intestine • Secretes bicarbonate into small intestine to neutralize stomach acid Gallbladder • Stores and concentrates bile Mouth • Teeth chew food • Tongue positions and tastes food ORGANS: Appendix • No known digestive function Stomach • Stores and mixes food • Begins chemical digestion of protein by enzymes and acid • Regulates delivery to the small intestine Anus • Expels undigested material Rectum • Passageway for feces Sigmoid colon • Stores feces Large intestine • Absorbs the last of the water and nutrients • Stores waste material Small intestine • Digests proteins, fats, and carbohydrates • Absorbs most of the water and nutrients • Secretes digestive hormones and enzymes

3. Gastrointestinal (GI) Tract Wall Figure 14.2 Lumen Circular layer Longitudinal layer Lymph vessel Serosa • Connective tissue outer covering • Protects and anchors the digestive tract Mucosa • Mucous membrane layer • Lines the digestive tract Submucosa • Connective tissue layer • Contains blood vessels, lymph vessels, and nerves Muscularis • Two layers of smooth muscle • Responsible for motility of the digestive tract Vein Artery Nerve

4. Motility: Peristalsis Figure 14.3a

5. Motility: Segmentation Figure 14.3b

6. Salivary Glands Figure 14.5

7. Swallowing Figure 14.6a

8. Swallowing Figure 14.6b

9. Structure of the Stomach Wall Figure 14.7a–b

10. The Stomach Figure 14.7

11. Peristalsis Figure 14.8

12. The Wall of the Small Intestine Figure 14.9a–b

13. The Wall of the Small Intestine Figure 14.9c

14. Accessory Organs: Aid Digestion and Absorption Figure 14.10 Esophagus Liver • Produces bile (water and electrolytes, cholesterol, bile salts, lecithin, and pigments) Gallbladder • Stores and concentrates bile • Delivers bile to the duodenum via the common bile duct Pancreas • Secretes enzymes (proteases, amylase, lipase) • Produces sodium bicarbonate • Delivers these products to the duodenum via ducts Stomach Pancreatic duct Common bile duct Duodenum

15. Accessory Organs: Aid Digestion and Absorption Figure 14.11

16. Large Intestine Figure 14.12 Sigmoid colon Descending colon External anal sphincter (skeletal muscle) Anus Anal canal Rectum Internal anal sphincter (smooth muscle) Appendix Cecum Ileocecal valve Ascending colon Transverse colon Small intestine

17. Absorption of Proteins and Carbohydrates Figure 14.13

18. Absorption of Fats Figure 14.14

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37. Goblet cells

43. Nutrients: Utilized or Stored Until Needed Figure 14.15

44. Food Guide Pyramid Figure 14.16