1. Animal Nutrition Nutritional requirements Food types and feeding mechanisms Overview of food processing Mammalian digestive system

3. Nutritional Requirements Fuel Raw organic materials for biosynthesis Essential nutrients which must be obtained in a prefabricated form: vitamins, minerals Deficiencies include: kwashiokor-protein deficiency, starvation-insufficient calories,

5. Overview of Food Processing Four stages: ingestion, digestion, absorption, and elimination Ingestion-the act of eating Digestion-process of breaking down food into small molecules Absorption-uptake of small molecules Elimination-undigested material passes out of the digestive compartment

7. The Mammalian Digestive System Oral cavity-mechanical digestion, chemical digestion of starches Esophagus-conducts food to stomach, peristalsis Stomach-food storage, churning, chemical digestion, secretion (regulated by gastrin, lining protected Small intestine-digestion and absorption Large intestine- reclaims water, produce vitamin K, produce feces

11. How does the stomach avoid digesting itself? Food contact on lining stimulates gastrin to be secreted Gastrin targets parietal cells (to secrete HCl) and chief cells (to secrete pepsinogen) Pepsinogen is activated by HCl HCl also kills bacteria and denatures protein

13. The Villus: Functional Unit of the Mammalian Digestive System Found in the small intestine Contains a capillary and a lacteal Responsible for most absorption Human small intestine surface area = 300m 2