Bile contains all of the following except:

Correct Answer: B

Rationale: Bile does not contain potassium (K) as it is not a component of bile. The correct answer is B. Alkaline phosphatase is present in bile and aids in digestion. Cholesterol is also found in bile. CCK (Cholecystokinin) is a hormone released by the small intestine to stimulate bile release. Potassium is not a part of the composition of bile.

Correct Answer: C

Rationale: Infarction of the bowel may be caused by a volvulus, where the bowel twists on its mesentery, leading to compromised blood flow. Mesenteric artery thrombosis can also cause bowel infarction by obstructing blood supply. Therefore, the correct answer is C (both). Choices A and B are incorrect because each of them individually can cause bowel infarction.

Correct Answer: B

Rationale: The correct answer is B: Sodium-glucose co-transport system. This system involves the active transport of glucose across the small intestine epithelial cells with the help of sodium ions. This mechanism allows for the absorption of glucose against its concentration gradient, ensuring efficient uptake. Other choices are incorrect because: A) Simple passive diffusion is not efficient for glucose absorption due to its hydrophilic nature. C) Osmosis is the movement of water molecules, not glucose. D) Primary active transport involves the direct use of energy to transport molecules, which is not the case for glucose absorption in the small intestine.

Correct Answer: B

Rationale: Step-by-step rationale: 1. Gastric secretions contain intrinsic factor, essential for vitamin B12 absorption from the terminal ileum. 2. Intrinsic factor binds to vitamin B12 to facilitate its absorption. 3. Without intrinsic factor, vitamin B12 absorption is impaired, leading to pernicious anemia. 4. Therefore, choice B is correct. Summary: - Choice A is incorrect as gastric secretions increase, not decrease, when a person thinks of food. - Choice C is incorrect as hydrochloric acid (HCl) is secreted by parietal cells, not chief cells. - Choice D is incorrect as fat digestion primarily occurs in the small intestine with the help of pancreatic enzymes, not gastric secretions.

Correct Answer: A

Rationale: The correct answer is A: Amylase. Amylase is an enzyme that specifically breaks down carbohydrates into sugars in the mouth. It is produced by both salivary glands and pancreas. Protease (B) breaks down proteins, Lipase (C) breaks down fats, and Pepsin (D) breaks down proteins in the stomach. Therefore, A is the correct answer for the enzyme responsible for breaking down carbohydrates in the mouth.