BIOL 238

Sample Questions

The Digestive System

1. Enzymes from the _____ produce the final stages of carbohydrate digestion.

(A) brush border, (B) stomach, (C) saliva, (D) pancreas.

2, 3. The combination of the enzyme precursor ___(2)___ and ___(3)___ produces the enzyme responsible for the initial digestion of polypeptides.

(A) pepsin, (B) pepsinogen, (C) dipeptidase, (D) gastin, (E) H⁺

4. Brush-border enzymes are produced by microvilli on cells lining the:

(A) gastric pits, (B) haustra, (C) small intestine villi, (D) pancreatic duct, (E) cystic duct.

5. The enzyme whose action produces maltose is:

(A) pepsin, (B) maltase, (C) amylase, (D) dipeptidase.

6. In anticipation of receiving food stimulates secretion of gastric juice:

(A) gastrin, (B) CCK, (C) secretin, (D) GIP, (E) the vagus nerve.

7. In response to fat and protein-rich acid chyme entering the duodenum is secreted which stimulates both the gallbladder and pancreas.

(A) GIP, (B) gastrin, (C) CCK, (D) secretin, (E) GIP.

8. In addition to the above response, the hormone identified:

(A) causes relaxation of the sphincter of Oddi,

(B) inhibits secretion and motility in the stomach,

(C) stimulates bile production by the liver,

(D) all of the above,

(E) A and B only.

9, 10. Negative feedback in the control of gastric emptying occurs in the (9) and is primarily

due to release of (10) .

Choices for 9: (A) gastric phase, (B) intestinal phase,

Choices for 10: (C) gastrin, (D) GIP, (E) enterokinase.

11. Co-transport depending on the unequal distribution of Na⁺ is used to move into mucosal cells.

(A) certain monosaccharides, (B) amino acids, (C) monoglycerides,

(D) all of the above, (E) A and B only.

12. Micelles are instrumental in the transport of into mucosal cells.

(A) all monosaccharides, (B) amino acids, (C) fat soluble vitamins, (D) fatty acids,

(E) both C and D.

13, 14. Once transported into mucosal cells fats are converted into (13) , and then transported directly into

the (14) .

Choices for 13: (A) micelles, (B) chylomicrons, (C) high density lipoproteins,

Choices for 14: (A) lamina propria, (B) Lymph capillaries, (C) blood capillaries.

15. The enterogastric reflex:

(1) inhibits motility in the stomach, (2) forcefully contracts the pyloric sphincter,

(3) causes the gastrocolic reflex, (4) stimulates the ileocecal sphincter

(A) Answer 1 only, (B) Both 1 and 2, (C) 1, 2, and 3, but not 4, (D) All of the above

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16 through 20 Matching: Answers may be used more than once or not at all.

(A) esophagus, (B) stomach, (C) duodenum, (D) ileum, (E) colon

16. Contains three complete layers of smooth muscle

17. Contains both smooth and skeletal muscle

18. Its longitudinal muscle layer is in the form of three separate bands.

19. Lined with stratified squamous epithelium.

20. Most of the lining is composed of mucus surface cells (MSC) which provide a continuous mucus layer to protect against acid.