A tumor producing large amounts of the intestinal hormone GIP may result in:

Correct Answer: A

Rationale: The correct answer is A: Hyperglycemia. GIP (gastric inhibitory polypeptide) is released in response to food intake to stimulate insulin release and inhibit glucagon secretion, leading to reduced blood glucose levels. Excessive GIP production from a tumor can result in excessive insulin release, causing hypoglycemia. This is why the correct answer is hyperglycemia. Choices B, C, and D are incorrect as they do not align with the physiological effects of GIP.

Correct Answer: B

Rationale: The correct answer is B because a filling defect on a barium examination indicates that something is protruding into the lumen, displacing the barium. This means there is an abnormality or mass present that prevents the barium from flowing uniformly. Choice A is incorrect because a filling defect does not necessarily indicate local dilation or outpouching. Choice C is incorrect because it combines both A and B, which is not always the case. Choice D is incorrect as there is indeed something causing the barium to be displaced in the lumen.

Correct Answer: C

Rationale: The correct answer is C: small intestine. Primary carcinoma is least common in the small intestine due to its relatively lower exposure to carcinogens and slower cellular turnover compared to other segments like the colon. The esophagus is prone to carcinoma due to chronic irritation from acid reflux. The stomach is susceptible due to factors like Helicobacter pylori infection and dietary habits. The colon is at higher risk due to frequent exposure to fecal carcinogens. In summary, the small intestine has the least incidence of primary carcinoma due to lower exposure to risk factors.

Correct Answer: D

Rationale: The correct answer is D: Amylase. Gastric secretion does not contain amylase. Amylase is an enzyme produced by the pancreas and salivary glands to break down carbohydrates. In the stomach, gastric secretions mainly consist of hydrochloric acid (HCl) for digestion, intrinsic factor (IF) for vitamin B12 absorption, and mucous to protect the stomach lining. Therefore, amylase is not a component of gastric secretion.

Correct Answer: C

Rationale: The correct answer is C because during swallowing, the swallowing center in the medulla oblongata inhibits the medullary respiratory center to prevent aspiration. This coordination ensures that breathing is temporarily halted to prevent food or liquid from entering the airway. Choices A, B, and D are incorrect because not all processes of deglutition are under voluntary control, the vocal folds actually close to protect the airway during swallowing, and the movement of the food bolus down the esophagus is facilitated by peristalsis rather than gravity.