GIT Physiology Exam Questions — Notes OmpathStudy

GIT Physiology Exam Questions Section A: Multiple Choice Questions 1. How is the HCO3- content of saliva altered in the presence of food? a) Food stimulates the parasympathetic nervous system to reduce HCO3- secretion into the saliva. b) Food stimulates the sympathetic nervous system to increase HCO3- secretion into saliva. c) Food stimulates the parasympathetic nervous system to increase HCO3- secretion into the saliva. d) Food inhibits parasympathetic input, which in turn reduces HCO3- secretion into the saliva. Answer: c) Food stimulates the parasympathetic nervous system to increase HCO3- secretion into the saliva. Explanation: The parasympathetic nervous system , activated during eating, stimulates salivary glands to secrete saliva with increased bicarbonate (HCO3-) to neutralize acids and aid digestion. 2. What type of cells produce somatostatin in the stomach and duodenum? a) D cells b) Acinar cells c) I cells d) S cells Answer: a) D cells Explanation: D cells , located in the stomach and duodenum, produce somatostatin , which inhibits the release of other gastrointestinal hormones and regulates gastric acid secretion . 3. What enzyme is involved in the combination of water and carbon dioxide during carbonic acid production in the pancreas ? a) Carbonic dehydratase b) Carbonic reductase c) Carbonic anhydrase d) Carbonic hydratase Answer: c) Carbonic anhydrase Explanation: Carbonic anhydrase catalyzes the reaction between water and carbon dioxide to form carbonic acid , which dissociates into bicarbonate (HCO3-) in the pancreas . 4. Which peptide hormone released by the stomach wall stimulates appetite ? a) Insulin b) Ghrelin c) Leptin d) Somatostatin Answer: b) Ghrelin Explanation: Ghrelin , produced by the stomach wall , is known as the " hunger hormone " and stimulates appetite , particularly before meals. 5. In which section of the gastric pits are mucus-secreting cells found? a) Approximately halfway down the gastric pit b) The neck of the gastric pit c) Along the entire length of the gastric pits d) Acinar cells Answer: b) The neck of the gastric pit Explanation: Mucus-secreting cells are primarily located in the neck region of gastric pits , where they produce mucus to protect the gastric mucosa . 6. Which of the following is not part of the exocrine pancreas ? a) Acinar tissue b) Duct tissue c) Islets of Langerhans d) Digestive enzymes Answer: c) Islets of Langerhans Explanation: The Islets of Langerhans are part of the endocrine pancreas , responsible for hormone production (e.g., insulin , glucagon ). 7. What effect does somatostatin have on pancreatic exocrine secretion ? a) Inhibits all gastric secretions, resulting in an overall increase in exocrine secretion b) Increases bicarbonate secretion, which stimulates an overall reduction in exocrine secretion c) Acts to increase histamine secretion from the stomach, promoting an overall increase in pancreatic exocrine secretions d) Inhibits CCK-stimulated enzyme secretion to cause an overall reduction in pancreatic exocrine secretion Answer: d) Inhibits CCK-stimulated enzyme secretion to cause an overall reduction in pancreatic exocrine secretion 8. What is the role of bicarbonate secreted by the pancreas ? a) Reduce pH of the small intestine b) Neutralize stomach acid c) Decrease activity of digestive enzymes d) Break down the mucous layer Answer: b) Neutralize stomach acid 9. What happens to the sodium concentration of saliva during ductal modification ? a) Sodium concentration increases b) Sodium concentration decreases c) Sodium concentration does not change d) Sodium is not present in the saliva at this stage Answer: b) Sodium concentration decreases Explanation: During ductal modification , salivary ducts reabsorb sodium , reducing its concentration in saliva. 10. Which cell releases cholecystokinin (CCK) ? a) I cells b) N cells c) K cells d) Enterochromaffin cells Answer: a) I cells 11. What is the role of bicarbonate in the composition of gastric mucus ? a) To maintain the viscosity of the mucus b) To negatively regulate mucus production c) To increase the pH of the mucus d) To negatively regulate acid production Answer: c) To increase the pH of the mucus 12. What effect does sympathetic nervous system stimulation have on the blood flow to the salivary glands ? a) Sympathetic stimulation releases noradrenaline, which acts at adrenergic receptors to increase the blood flow b) Sympathetic stimulation releases acetylcholine to increase blood flow c) Sympathetic stimulation releases noradrenaline , which acts at adrenergic receptors to decrease the blood flow d) Sympathetic stimulation releases acetylcholine to decrease blood flow Answer: c) Sympathetic stimulation releases noradrenaline, which acts at adrenergic receptors to decrease the blood flow 13. Where in the GI tract does most absorption of water and electrolytes occur? a) Stomach b) Small intestine c) Large intestine d) Kidney Answer: c) Large intestine 14. Which salivary enzyme he