Chapter Objectives

1. Distinguish among herbivores, carnivores, and omnivores
2. Describe the following feeding mechanisms and give examples of animals that use each
   1. filter-feeding
   2. deposit-feeding
   3. substrate-feeding
   4. fluid-feeding
3. Define digestion and describe why it is a necessary process
4. Explain how anhydro bonds are formed and describe the role of hydrolysis in digestion
5. Distinguish between intracellular and extracellular digestion
6. Explain why intracellular digestion must be sequestered in a food vacuole and give examples of organisms which digest their food in vacuoles
7. Define gastrovascular cavity and explain why extracellular digestive cavities are advantageous
8. Using Hydra as an example, describe how a gastrovascular cavity functions in both digestion and distribution of nutrients
9. List major animal phyla which use gastrovascular cavities for digestion
10. Describe advantages that complete digestive tracts have over gastrovascular cavities and list the major animal phyla with alimentary tracts
11. Define peristalsis and describe its role in the digestive tract
12. Describe how salivation is controlled and list the functions of saliva
13. Describe the role of salivary amylase in digestion
14. Describe the sequence of events which occur as a result of the swallowing reflex
15. Describe the function of the esophagus and explain how peristalsis in the esophagus is controlled
16. Describe the role of cardiac and pyloric sphincters
17. List the 3 types of secretory cells found in stomach epithelium and what substances they secrete
18. Recall the normal pH of the stomach and explain the function of stomach acid
19. Describe the function of pepsin
20. Explain why the stomach normally does not digest itself
21. Explain how pepsin and acid secretion are regulated and describe the roles of the hormones gastrin and enterogastrone
22. Describe the cause of ulcers and explain why they are frequently found in the duodenum
23. Explain how chyme is moved through the small intestine
24. Describe the sequence of events which occur in response to acid chyme entering the duodenum. Include the roles of
    1. secretin
    2. bicarbonate
    3. cholecystokinin (CCK)
    4. gall bladder
    5. bile
    6. pancreatic enzymes
    7. enterogastrone
25. Describe how pancreatic zymogens for proteolytic enzymes are activated in the duodenum and include the role of the intestinal enzyme enterokinase
26. Describe enzymatic digestion of carbohydrates, proteins, lipids, and nucleic acids, including the reactants and products for each enzymatic reaction and whether they occur in the
    1. oral cavity
    2. stomach
    3. lumen of small intestine
    4. brush border of small intestine
27. Explain the function of bile, describe where it is produced and stored, and describe its composition
28. State whether the lumen of the digestive tract is technically inside or outside the body
29. Explain where nutrient absorption occurs
30. Explain why the many folds, villi, and microvilli are important in the small intestine
31. Describe how specific nutrients are absorbed across the intestinal epithelium and across the capillary or lacteal wall and indicate whether the transport is with or against the concentration gradient
32. Explain what happens to glycerol and fatty acids after they are absorbed into the intestinal epithelium and describe the fate of chylomicrons and lipoproteins
33. Explain the function of the hepatic portal vein
34. Explain where in the digestive tract the most reabsorption of water occurs
35. Describe the composition of feces and explain the main source of vitamin K for humans
36. Give examples of vertebrates with the following digestive adaptations and explain how these adaptations are related to diet
    1. variation in dentition
    2. variation in length of digestive tract
    3. fermentation chambers
37. Explain why animals need a nutritionally adequate diet
38. Describe the effects of undernourishment or starvation
39. List some risks of obesity
40. Distinguish between malnourished and undernourished
41. List 4 classes of essential nutrients and describe what happens if they are deficient in the diet
42. List and distinguish between water-soluble and fat-soluble vitamins and explain how they are used by the body
43. Describe the dietary sources, major body functions, and deficiency effects for the following required minerals in the human diet
    1. calcium
    2. phosphorus
    3. sulfur
    4. potassium
    5. chlorine
    6. sodium
    7. magnesium
    8. iron

Chapter Terms:

Chapter Outline Framework

1. Nutritional Requirements
   1. Animals are heterotrophs that require food for fuel, carbon skeletons, and essential nutrients
   2. Homeostatic mechanisms manage an animal's fuel
   3. An animal's diet must supply essential nutrients and carbon skeletons for biosynthesis
2. Food Types Feeding Mechanisms
1. Most animals are opportunistic feeders
2. Diverse feeding adaptations have evolved among animals
3. Overview of Food Processing
1. 4 main stages of food processing
   1. ingestion
   2. digestion
   3. absorption
   4. elimination
2. Digestion occurs in specialized compartments
4. Mammalian Digestive System
   1. Oral cavity, pharynx, and esophagus initiate food processing
   2. Stomach stores food and performs preliminary digestion
   3. Small intestine is major organ of digestion and absorption
   4. Hormones help regulate digestion
   5. Reclaiming water is major function of large intestine
5. Evolutionary Adaptations of Vertebrate Digestive System
1. Structural adaptations of digestive system often associated with diet
2. Symbiotic organisms help nourish many vertebrates

back to top