10. Describe the movement of fat digestion products from the
intestinal lumen to a lacteal.
11. How does the absorption of fat-soluble vitamins differ from
that of water-soluble vitamins?
12. Specify two conditions that may lead to failure to absorb
13. How are salts and water absorbed in the small intestine?
14. Describe the role of ferritin in the absorption of iron.
15. List the four types of stimuli that initiate most gastrointestinal
16. Describe the location of the enteric nervous system and its role
in both short and long reﬂ exes.
17. Name the four best understood gastrointestinal hormones and
state their major functions.
18. Describe the neural reﬂ exes leading to increased salivary
19. Describe the sequence of events that occur during swallowing.
20. List the cephalic, gastric, and intestinal phase stimuli that
stimulate or inhibit acid secretion by the stomach.
21. Describe the function of gastrin and the factors controlling its
22. By what mechanism is pepsinogen converted to pepsin in the
23. Describe the factors that control gastric emptying.
24. Describe the mechanisms controlling pancreatic secretion of
bicarbonate and enzymes.
25. How are pancreatic proteolytic enzymes activated in the small
26. List the major constituents of bile.
27. Describe the recycling of bile salts by the enterohepatic
28. What determines the rate of bile secretion by the liver?
29. Describe the effects of secretin and CCK on the bile ducts and
30. What causes water to move from the blood to the lumen of the
duodenum following gastric emptying?
31. Describe the type of intestinal motility found during and shortly
after a meal and the type found several hours after a meal.
32. Describe the production of ﬂ atus by the large intestine.
33. Describe the factors that initiate and control defecation.
34. Why is the stomach’s wall normally not digested by the acid
and digestive enzymes in the lumen?
35. Describe the process of vomiting.
36. What are the consequences of blocking the common bile duct
with a gallstone?
37. What are the consequences of the failure to digest lactose in
the small intestine?
38. Contrast the factors that cause constipation with those that
short reﬂ ex
sphincter of Oddi
upper esophageal sphincter
inﬂ ammatory bowel disease
syrup of ipecac
1. List the four processes that accomplish the functions of the
2. List the primary functions performed by each of the organs in
the gastrointestinal system.
3. Approximately how much ﬂ uid is secreted into the
gastrointestinal tract each day compared with the amount of
food and drink ingested? How much of this appears in the feces?
4. What structures are responsible for the large surface area of the
5. Where does the venous blood go after leaving the small intestine?
6. Identify the enzymes involved in carbohydrate digestion and the
mechanism of carbohydrate absorption in the small intestine.
7. List three ways in which proteins or their digestion products
can be absorbed from the small intestine.
8. Describe the process of fat emulsiﬁ cation.
9. What is the role of micelles in fat absorption?
Chapter 15 Test Questions
(Answers appear in Appendix A.)
Questions 1–4: Match the following gastrointestinal hormones
to their descriptions.
1. It is stimulated by the presence of acid in the small intestine and
stimulates bicarbonate release from the pancreas and bile ducts.
2. It is stimulated by glucose and fat in the small intestine and
increases insulin and ampliﬁ es the insulin responses to glucose.
3. It is inhibited by acid in the stomach and stimulates acid
secretion from the stomach.
4. It is stimulated by amino acids and fatty acids in the small
intestine and stimulates pancreatic enzyme secretion.
5. Which of the following is true about pepsin?
a. Most pepsin is released directly from chief cells.
b. Pepsin is most active at high pH.
c. Pepsin is essential for protein digestion.
d. Pepsin accelerates protein digestion.
e. Pepsin accelerates fat digestion.