Glucose absorption from the small intestine is by:

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: 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.

Correct Answer: A

Rationale: The correct answer is A: mouth. Mechanical digestion begins in the mouth where food is chewed and mixed with saliva, breaking down into smaller pieces for easier swallowing and digestion. This process increases the surface area of food for enzymes to act upon. The stomach (B) primarily performs chemical digestion, the small intestine (C) is where most chemical digestion and absorption occur, and the large intestine (D) is mainly responsible for water absorption and formation of feces. Thus, the mouth is the correct choice for the beginning of mechanical digestion.

Correct Answer: D

Rationale: Rationale for Correct Answer D: - Psyllium is a bulk-forming laxative that works by absorbing water in the intestines, forming a gel-like mass that helps with bowel movements. - Taking large amounts of fluid is essential when using psyllium to prevent the gel-like mass from hardening and causing impaction or bowel obstruction. - Adequate fluid intake is crucial for the safe and effective use of psyllium as a laxative. Summary of Incorrect Choices: - Choice A is incorrect because fiber-containing laxatives like psyllium do not directly impact the absorption of fat-soluble vitamins. - Choice B is incorrect as dietary sources of fiber should not be eliminated entirely but rather balanced to prevent excessive gas. - Choice C is incorrect as all medications, including laxatives, can have potential adverse effects; however, psyllium is generally well-tolerated when used appropriately.

Correct Answer: D

Rationale: The correct answer is D because esomeprazole (Nexium) is a proton pump inhibitor that works by decreasing stomach acid production, thereby treating gastroesophageal reflux disease. This explanation is important for the patient to understand the mechanism of action of the medication. Choice A is incorrect because esomeprazole does not increase the rate of gastric emptying; instead, it reduces acid production. Choice B is incorrect because esomeprazole does not neutralize stomach acid immediately; it takes a few days to reach its full effect. Choice C is incorrect because esomeprazole does not coat and protect the stomach and esophagus; it works by reducing acid production. In summary, the correct answer is D because it accurately describes how esomeprazole works to manage recurring heartburn by decreasing stomach acid production, which is essential for treating gastroesophageal reflux disease.