Which of the following is NOT an action of insulin?

Correct Answer: C

Rationale: Rationale: C is correct because insulin does not stimulate the breakdown of glycogen. Insulin promotes the storage of glucose as glycogen, not its breakdown. A, B, and D are incorrect because insulin does stimulate cellular absorption of glucose, usage of glucose for energy, and lowers blood glucose levels, respectively. Insulin's main role is to facilitate the uptake and storage of glucose, not its breakdown.

Correct Answer: D

Rationale: The Islets of Langerhans are clusters of cells in the pancreas that regulate blood sugar levels. Choice D, Endocrine pancreas, is correct because the Islets of Langerhans are specifically located in the pancreas. Choices A, B, and C are incorrect because the Islets of Langerhans are not found in the anterior pituitary, cortex, or spleen. The pancreas is the primary organ associated with blood sugar regulation, making it the correct location for the Islets of Langerhans.

Correct Answer: D

Rationale: The correct answer is D: Kidney. Antidiuretic hormone (ADH) acts on the kidneys to regulate water balance by increasing water reabsorption, thus reducing urine output. This hormone helps maintain proper fluid balance in the body. The other choices (A: Pancreas, B: Liver, C: Uterus) are incorrect because they do not play a direct role in water balance regulation or response to ADH stimulation. The kidney is the main target organ for ADH due to its crucial role in water reabsorption and urine concentration.

Correct Answer: D

Rationale: The correct answer is D: amylase. Gastric juice primarily contains hydrochloric acid, pepsinogen, and mucus, but not amylase. Amylase is an enzyme produced in the mouth and pancreas that helps break down carbohydrates, not typically found in gastric juice. HPO42- is a phosphate ion present in gastric juice. Lipase is an enzyme that aids in the digestion of fats and can be found in pancreatic juice, not gastric juice. Mucus is secreted by the stomach lining to protect it from the acidic environment of gastric juice.

Correct Answer: B

Rationale: The correct answer is B: increased gastric motility and emptying. CCK, or cholecystokinin, is a hormone released by the small intestine in response to the presence of fats. Its main actions include stimulating gallbladder contraction (A) to release bile for fat digestion, triggering the secretion of pancreatic juice (D) containing digestive enzymes, and inhibiting gastric motility and emptying. Therefore, increased gastric motility and emptying (choice B) is NOT an action of CCK. This is because CCK acts to slow down gastric emptying to allow for effective digestion of fats in the small intestine. Choices A, C, and D are all correct actions of CCK based on its role in the digestive process.