564
Chapter 15
CLINICAL TERMS
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
vitamin B
12
.
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
refl exes.
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
secretion.
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
secretion.
22. By what mechanism is pepsinogen converted to pepsin in the
stomach?
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
intestine?
26. List the major constituents of bile.
27. Describe the recycling of bile salts by the enterohepatic
circulation.
28. What determines the rate of bile secretion by the liver?
29. Describe the effects of secretin and CCK on the bile ducts and
gallbladder.
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
produce diarrhea.
serosa
535
short refl ex
541
small intestine
532
somatostatin
545
sphincter
544
sphincter of Oddi
554
stomach
530
submucosa
535
submucosal plexus
535
swallowing center
543
trypsin
537
trypsinogen
552
upper esophageal sphincter
544
villus
536
vomiting center
559
zymogen
548
biopsy
557
bronchoscopy
557
cholecystectomy
560
cholera
561
colitis
536
colonoscopy
557
constipation
561
Crohn’s disease
536
cyclosporine
560
diarrhea
561
dumping syndrome
551
emetic
559
endoscope
557
gallstones
559
gastritis
558
gastroesophageal refl
ux
545
heartburn
545
Helicobacter pylori
558
hemochromatosis
540
hemolytic jaundice
559
infl ammatory bowel disease
536
jaundice
559
lactose intolerance
560
laxative
561
malabsorption
539
nontropical sprue
539
pernicious anemia
540
phlebotomy
540
retching
559
sigmoidoscopy
557
Sjögren’s syndrome
543
steatorrhea
559
sulfasalazine
560
syrup of ipecac
559
tacrolimus
560
traveler’s diarrhea
561
ulcer
557
REVIEW QUESTIONS
1. List the four processes that accomplish the functions of the
gastrointestinal system.
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
small intestine?
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.
a. gastrin
c. secretin
b. CCK
d. GIP
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.
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