Biology 107

Study Guide: Animal Nutrition II.

Chapter 41

1. Define peristalsis and describe its role in the digestive process.

2. How is salivation controlled? What are the functions of saliva?

3. What is the sequence of events in swallowing? Which portions of the sequence are under voluntary control, and which are involuntary?

4. What are the secretory cells of the stomach?

5. Why doesn’t the stomach digest itself? Why are zymogens important in preventing digestion of stomach cells? Why is it important that gastrin stimulates mitosis in mucosa cells?

6. Describe the sequence of events which occur in response to acid chyme entering the duodenum. Include the roles of secretin, bicarbonate, CCK, gall bladder, bile, pancreatic enzymes, and enterogastrone.

7. Describe how pancreatic zymogens for proteolytic enzymes are activated in the duodenum and include the role of the intestinal enzyme enteropeptidase.

8. Where does most nutrient absorption occur? Why are the many folds, villi, and microvilli important for nutrient absorption?

9. Sugars and amino acids that are absorbed are immediately transported to the liver, while fats are not directly transported to the liver. What is the anatomical reason for this?

10. Where does most reabsorption of water occur? What is the main source of vitamin K for humans?