Chapter 9: Gastrointestinal System Martin Caon Examination Questions and Answers in Basic Anatomy and Physiology Third Edition

Martin Caon Examination Questions and Answers in Basic Anatomy and Physiology Third Edition Chapter 9: Gastrointestinal System 9.1 Anatomy and Function 1. Which type of cell produces hydrochloric acid? a. Zymogenic cells b. Parietal cells c. Chief cells d. Enteroendocrine cells Answer is B: The parietal cells of gastric glands produce hydrochloric acid. (Zymogenic cells are the same as chief cells, and they produce pepsinogen.) 2. What is the role of gastrin in the digestive system? a. To stimulate the release of bile and pancreatic juice b. To stimulate gastric secretion c. To activate pepsinogen d. To hydrolyse proteins to polypeptides Answer is B: Gastrin is a hormone that stimulates gastric secretion (from the stomach wall). 3. What feature of the small intestine enhances its ability to absorb digested food? a. Its large surface area b. The gaps between adjacent epithelial cells c. Secretion of the hormone absorptin d. Its longer length compared to the large intestine Answer is A: The large surface area allows the products of digestion ample opportunity to make contact with the absorbing surface. “Absorptin” is not a hormone. 4. Which of the following gut structures are listed in the correct order that food would pass through them, from input to exit? a. Pyloric sphincter, ileum, jejunum, transverse colon b. Pancreas, jejunum, ascending colon, sigmoid colon c. Ileum, duodenum, descending colon, ascending colon d. Duodenum, ileum, caecum, transverse colon Answer is D: Jejunum is before the ileum; food does not pass through the pancreas; duodenum is before the ileum. 5. Which statement about the layers of the alimentary canal is correct? a. The serosa absorbs the products of digestion. b. The mucosa protects against self-digestion. c. The submucosa is involved in segmentation and peristalsis d. The muscularis externa is dense connective tissue. Answer is B: The mucosa (not serosa) absorbs the products of digestion; the muscularis externa causes segmentation and peristalsis; the submucosa (not muscularis) is dense connective tissue. 6. Which of the following pairs of substances are NOT secreted by the stomach as part of “gastric juice”? a. Hydrochloric acid and pepsinogen b. Hormones and intrinsic factor c. Nuclease and amylase d. Mucus and gastrin Answer is C: Nuclease and amylase are enzymes secreted by the pancreas. 7. From which of the gut structures below is most digested food absorbed? a. Duodenum b. Stomach c. Ileum d. Ascending colon Answer is C: Ileum is the part of the small intestine distal to the duodenum which has a structure suited for absorption. 8. What is the term applied to the production of glucose from non-carbohydrate molecules? a. Deamination b. Transamination c. Glycogenolysis d. Gluconeogenesis Answer is D: Gluco refers to glucose; neo = new; genesis = producing. (Glycogenolysis is the production of glucose form glycogen—by lysis.) 9. What is the purpose of “intrinsic factor” in gastric juice? a. To activate pepsinogen b. To assist with the absorption of vitamin B12 c. To protect the stomach lining against hydrochloric acid d. To stimulate the release of gastrin Answer is B: Vitamin B12 is a large molecule which cannot be absorbed without forming a complex with intrinsic factor. 10. Which of the following does NOT contribute to increasing the surface area of the small intestine? a. The brush border b. Plicae circulars c. Intestinal crypts d. Villi Answer is C: The crypts produce the secretion known as intestinal juice. 11. Which layer of the gastrointestinal tract is in contact with the contents of the gut? a. Muscularis externa b. Mucosa c. Serosa d. Submucosa Answer is B: It secretes mucus and absorbs the products of digestion. 12. What is the name given to the process of moving the gut contents along the tract in the right direction? a. Peristalsis b. Emesis c. Segmentation d. Deglutition Answer is A: Segmentation is “to and fro” movement about the one spot. 13. Which of the following substances is NOT produced by the cells of the gastric glands? a. Mucus b. Hydrochloric acid c. Gastrin d. Pepsin Answer is A: Mucus cells are in the epithelium, not in the gastric glands, and produce mucus. 14. Which hormone stimulates the release of bile and pancreatic juice? a. Cholecystokinin b. Secretin c. Intestinal gastrin d. Pepsin Answer is A: Duodenum produces and releases CCK when protein and fats enter the duodenum. 15. Where is the gastro-oesophageal sphincter? a. Between the stomach and the duodenum b. Between the stomach and the caecum c. At the entrance to the stomach d. Before the external anal sphincter Answer is C: It is where the oesophagus enters the stomach. It prevents the stomach contents refluxing into the oesophagus. 16. Which sections of the gut perform the majority of the digestion of food and absorption of the digested products? a. Stomach and duodenum b. Jejunum and ileum c. Ascending colon and transverse colon d. Duodenum and jejunum Answer is D: While a small amount of digestion and absorption occurs in the stomach, most occurs in the duodenum (which receives pancreatic enzymes and bile) and the jejunum (which is adapted for absorption).