Bile secretion is stimulated by the hormone ______ in response to ______.

Correct Answer: B

Rationale: The correct answer is B: cholecystokinin; low pH of the chyme. Cholecystokinin is released in response to the presence of fats and proteins in the duodenum. This hormone stimulates the gallbladder to release bile into the small intestine to aid in the digestion and absorption of fats. The low pH of the chyme triggers the release of cholecystokinin as it indicates the presence of undigested fats and proteins, signaling the need for more bile to aid in their digestion. Choices A, C, and D are incorrect because cholecystokinin is specifically released in response to the low pH of the chyme, not the high pH. Secretin, on the other hand, is released in response to the high pH of the chyme to stimulate bicarbonate release from the pancreas to neutralize the acidic chyme, not for bile secretion.

Correct Answer: C

Rationale: The correct answer is C because hemicelluloses, pectins, and inulin are indeed rapidly fermented to short-chain fatty acids in the colon, providing trophic effects. This is supported by scientific evidence. Choice A is incorrect because the main end products of fermentation of dietary fiber are short-chain fatty acids, not malic, succinic, and propionic acids. Choice B is incorrect as not all forms of fiber are completely fermented within 24 hours, and the time frame can vary. Choice D is incorrect because stool bulking is primarily attributed to soluble fibers, which hold water and increase stool bulk, rather than insoluble fibers like cellulose.

Correct Answer: D

Rationale: The correct answer is D (P, Q, R, and S). P is correct because mechanical digestion does occur in the stomach through the churning action of the stomach muscles. Q is correct as cholecystokinin, gastrin, and secretin are indeed produced by enteroendocrine cells in the gastrointestinal tract. R is correct because the pancreas, small intestine, and salivary glands produce digestive enzymes to aid in the breakdown of food. S is correct as mucous neck cells, chief cells, and parietal cells are all present in the stomach and play roles in the digestion process. Therefore, all options P, Q, R, and S are correct, making answer choice D the correct one.

Correct Answer: A

Rationale: Rationale: Creatine primarily benefits high-intensity, short-duration activities by aiding in quick energy production through ATP regeneration. All-out sprints fall under this category, making creatine supplementation effective. In contrast, choices B and C involve longer durations where creatine's benefits are less pronounced. Choice D is incorrect as creatine has been shown to enhance performance in specific exercise scenarios.

Correct Answer: C

Rationale: The correct order for administering TPN through a central line starts with checking the solution for cloudiness or turbidity to ensure it's safe for infusion. This step is crucial to prevent potential complications such as infection or embolism. Aseptic technique (Choice A) is important but comes later after verifying solution clarity. Threading the IV tubing (Choice B) and connecting it to the central line (Choice D) should follow after ensuring the solution is clear. These steps are all essential but must be done in the correct order to prioritize patient safety and prevent adverse effects.