Which of the following is not a function of insulin?

Correct Answer: C

Rationale: The correct answer is C: Stimulating hepatic gluconeogenesis. Insulin's primary function is to lower blood glucose levels by promoting glucose uptake in cells and inhibiting gluconeogenesis in the liver. Choice A is correct as insulin helps lower blood glucose levels. Choice B is correct as insulin promotes protein synthesis. Choice D is correct as insulin promotes fatty acid synthesis to store excess glucose as fat. Therefore, choice C is incorrect as insulin actually inhibits hepatic gluconeogenesis rather than stimulating it.

Correct Answer: A

Rationale: Step-by-step rationale: 1. Glucagon is a hormone secreted by the pancreas. 2. It is released in response to low blood glucose levels to increase blood sugar. 3. Glucagon stimulates the liver to release stored glucose into the bloodstream. 4. Choice A is correct as it accurately describes the function of glucagon. Summary: Choice B is incorrect because glucagon does not regulate sodium and water balance. Choice C is incorrect as glucagon is not a steroid hormone. Choice D is incorrect as glucagon is not a glucocorticoid hormone.

Correct Answer: B

Rationale: The correct answer is B: Pineal gland. The pineal gland produces melatonin, a hormone that regulates the body's circadian rhythm, including sleep-wake cycles. This gland is sensitive to light and darkness, influencing the body's internal clock. A: Thymus gland is responsible for immune function, not circadian rhythm. C: Parathyroid gland regulates calcium levels in the body, not circadian rhythm. D: Pituitary gland controls various other hormones but not specifically circadian rhythm.

Correct Answer: B

Rationale: The correct answer is B: Islets of Langerhans. These are clusters of cells in the pancreas responsible for producing hormones like insulin and glucagon. The islets regulate blood sugar levels. Nodules (A) are not specific to the pancreas. Pancreatic medulla (C) and pancreatic cortex (D) do not refer to the specific clusters of cells in the pancreas that produce hormones.

Correct Answer: B

Rationale: The correct answer is B: adrenal glands. The adrenal glands are located on top of the kidneys and secrete hormones like cortisol and adrenaline, which play a key role in regulating metabolism and responding to stress. The pancreas (A) primarily regulates blood sugar levels. The thyroid gland (C) regulates metabolism and growth. The pituitary gland (D) controls several other endocrine glands but is not located on top of the kidneys and does not secrete metabolic stabilizers and stress regulators.