Your molars are most useful for _____.

1. Your molars are most useful for _____. • a. crushing and grinding a tough pizza • b. shredding meat off a bone • c. nipping the end of a carrot • d. none of the above

2. Which of the following is a function of mesenteries? • Mesenteries stabilize the organs of the abdominal cavity. • Mesenteries provide a route for blood vessels, nerves, and lymphatic vessels to and from the digestive tract. • Mesenteries prevent the intestines from becoming tangled with changes in body position. • All of the above are correct.

3. What is occurring when the soft palate and larynx elevate and the glottis closes? • a. swallowing • b. hiccupping • c. speaking • d. coughing

4. What is the primary source of flatus emitted from the intestines? • a. indole and skatole, two nitrogen-containing compounds • b. ammonia in the form of ammonium ions • c. indigestible carbohydrates acted on by bacteria • d. breakdown products of bilirubin

5. Which age-related changes in the digestive system are the results of decreased smooth muscle tone? • a. weaker peristaltic contractions and decrease in motility • b. thinning of epithelia of the mouth, esophagus, and anus • c. presence of hemorrhoids and esophageal reflux • d. both A and C

6. The four major layers of the GI tract are ______. • mucosa, digestive epithelium, lamina propria, and muscularis mucosa • mucosa, submucosa, muscularis externa, and serosa • submucosa, submucosal plexus, myenteric plexus, and serosa • none of the above

7. Which type of epithelium lines the intestines, and why? • simple squamous epithelium; because the absorption of nutrients occurs here • stratified squamous epithelium; because this area is subjected to abrasion • stratified cuboidal epithelium with cilia; because this area has many secretions from glands • simple columnar epithelium; because this area is involved with the absorption of nutrients

8. Which structures comprise a hepatic triad? • branches of the hepatic portal vein and hepatic artery, and a branch of the bile duct • branches of the cystic duct, common bile duct, and common hepatic duct • the superior mesenteric and splenic veins • none of the above

9. The major histological differences between the large intestine and small intestine are that the large intestine ______. • a. lacks villi, has abundant goblet cells, and has deeper intestinal glands • b. has longer villi, more microvilli, and plicae • c. has a larger nutrient absorptive surface • d. produces more enzymes and hormones

10. How do most chylomicrons enter the lymphatic system? • through the left and right subclavian veins • through lacteals • through the thoracic duct • through the hepatic portal system

11. Where in the human body will chemical digestion begin? • a. in the oral cavity • b. in the esophagus • c. in the stomach • d. none of the above

12. In which region(s) of the digestive tract does mechanical processing occur? a. in the mouth, by teeth and the tongue b. in the stomach, by churning c. in the small intestine, by segmentation d. all of the above

13. What is unusual about the muscularis externa of the esophagus? • It contains skeletal muscle along the superior one-third of its length. • It is surrounded by serosa. • It contains a combination of smooth muscle and skeletal muscle along the superior one-third of its length. • It contains nerves.

14. How do the regional specializations of the small intestine change along its length? • The duodenum has small villi and numerous mucous glands. • The jejunum has numerous villi for absorption. • The ileum contains aggregated lymphoid nodules. • All of the above are correct.

15. Where are the motor neurons that control smooth muscle contraction and glandular secretions of the GI tract located? • a. in the hypothalamus • b. in the submucosal plexus • c. in the myenteric plexus • d. in the muscularis mucosa

16. Which of the enzymes below would digest a particular carbohydrate into glucose and fructose? • a. lactase • b. maltase • c. sucrase • d. nuclease

17. The liver has more than 200 critical functions. Which of the following is NOTa liver function? • a. carbohydrate, lipid, and amino acid metabolism • b. vitamin and mineral storage • c. secretion of CCK, storage and concentration of bile • d. removal of antibodies, circulating hormones, and toxins

18. How do the roles of pepsinogen and HCI interact in the stomach? a. They both digest chyme. b. HCI is necessary to prevent pepsinogen from digesting proteins. c. They both kill microorganisms. d. HCI is necessary for the conversion of pepsinogen to pepsin.

19. What effect(s) does the secretion of CCK have on a fatty meal’s entrance to the duodenum? a. speeds up gastric emptying b. reduces rate and force of gastric contractions c. inhibits secretion of gastric acids and enzymes, slowing gastric emptying d. increases secretion of gastrin and decreases bile secretion

20. What effect does secretion of secretin by enteroendocrine cells of the duodenum have on the pancreas? • It stimulates the secretion of glucagon. • It stimulates production of pancreatic buffers that protect the duodenum. • It stimulates the secretion of insulin. • It promotes production and secretion of pancreatic enzymes.

21. Why is diarrhea potentially life threatening, but constipation is not? a. Wastes not eliminated as feces will be eliminated through urine. b. Constipation affects only gastric motility. c. Constipation causes edema. d. Diarrhea causes rapid water and electrolyte loss.

22. When a person suffers from chronic gastric ulcers, the branches of the vagus nerve serving the stomach are sometimes surgically severed. This is because the vagus nerve: • a. carries gastric pain sensations to the brain stem. • b. stimulates gastric motility through the parasympathetic division. • c. stimulates gastric secretions through the parasympathetic division. • d. causes ulcers due to overstimulation of the sympathetic nervous system.

23. Which disorder increases the rate at which fluids move into the peritoneal cavity? What condition results from excess fluids in the peritoneal cavity? a. liver disease; ascites b. gastric ulcers; internal bleeding c. diarrhea; dehydration d. Crohn’s disease; malabsorption

24. Which statement below is true with regard to gastric activity in the digestive system? a. Overstimulation of the sympathetic division of the ANS can inhibit the cephalic phase and lead to stomach upset. b. Caffeine and alcohol, when used as part of a meal, will inhibit gastric activity. c. Emotional states have no effect on gastric activity. d. All of the above are correct.

25. Which of the following statements correctly states the absorption of an ion/vitamin? a. Ca2+ absorption is inhibited by calcitriol. b. Vitamin B12 absorption occurs when it binds to extrinsic factor. c. Fat-soluble vitamins are absorbed from micelles along with dietary lipids. d. Aldosterone is a hormone that stimulates the absorption of K+.

26. How does taking fat-soluble vitamins on an empty stomach affect the absorption of those vitamins? • The vitamins are not absorbed, because they require presence of other lipids. • Having an empty stomach enhances absorption. • A different metabolic pathway is used when you have an empty stomach. • None of the above is correct.