The Digestive System

1. Compare different types of digestion in different organisms: intracellular vs. extracellular, complete vs. an incomplete digestive tract (gastrovascular cavity). Explain how the digestion is accomplished.

2. Define and explain the differences between suspension feeders, substrate feeders, fluid feeders, bulk feeders, herbivores, carnivores, omnivores, and saprobes. Know examples of each.

3. Know the foods we eat, why we eat them, what they are digested into, and how they are digested by hydrolysis: carbohydrates ® monosaccharides, proteins® amino acids, lipids ® glycerol and fatty acids, nucleic acids ® nucleotides.

4. Know what the dietary term "essential" means, and which items are essential for man.

5. Define the term vitamin. Define and distinguish between fat soluble and water soluble vitamins, explaining how often we need to consume them and why they do not need to be consumed at the same rate.

6. Know two examples of inorganic ions (minerals) and explain why they are needed.

7. Know and distinguish between the layers of the alimentary canal: serosa, muscularis, submucosa, mucosa.

8. Be able to trace food through the digestive tract, in order, and know the function of each part.

mouth - pharynx - esophagus - cardiac sphincter - stomach - pyloric sphincter - small intestine (duodenum, jejunum, ileum) - ileocecal valve, cecum (appendix) - large intestine (ascending, transverse, descending and sigmoid colon) - rectum - anus.

9. Explain the function of the epiglottis in the pharynx and the uvula on the soft palate and their role in the swallow reflex..

10. Know the difference between deciduous and permanent teeth and the generalized differences between the teeth of carnivores and herbivores.

11. Know the functions of the secretions from the following locations: mouth - saliva (mucus, enzyme), stomach (mucus, HCl, enzyme, parietal vs. chief cells), small intestine (enzymes), liver (bicarbonate, bile, gall bladder), pancreas (bicarbonate, enzymes), large intestine (mucus, alkaline fluids).

12. Know the composition and different functions of bile (bile salts, bile pigments, bicarbonate.)

13. Be able to describe the hormonal control of the secretion of digestive fluids. Know where the four hormones are secreted and what the four hormones trigger: gastrin, enterogastrone, secretin, cholecystokinin.

14. Know all the digestive enzymes, where they are made, where they act, what their substrates are, what they break the food into: amylase (2 forms), disaccharidases, lipase, pepsin, trypsin, chymotrypsin, enteropeptidase, aminopeptidase, carboxypeptidase, dipeptidase, nucleases (DNase, RNase).

15. Know the different functions of endopeptidases and exopeptidases and know which peptidases are which.

16. Know the significance of the "ogen" ending on pepsin, trypsin, and chymotrypsin.

17. Know and explain how the digested nutrients pass into the blood, either directly to the capillaries or indirectly through the lymph. Know which foods do which.

18. Explain how water is reabsorbed in the colon and the consequences of absorbing too much or too little water.

19. Know the all various functions of the liver.

20. Explain specializations associated with herbivores, such as the ruminants and those that utilize the cecum.

21. Misc. terms: bolus, chyme, lacteal, peristalsis, rugae, villi, microvilli (brush border), goblet cells, chylomicrons, hepatic portal vein.