Which gland produces cortisol?

Correct Answer: C

Rationale: The correct answer is C, the adrenal glands. The adrenal glands are responsible for producing cortisol, a hormone that helps regulate various functions in the body, such as metabolism, immune response, and stress response. The testes (A) produce testosterone, the ovaries (B) produce estrogen and progesterone, and the hypothalamus (D) regulates the release of hormones from the pituitary gland but does not produce cortisol directly. Therefore, choices A, B, and D are incorrect in this context.

Correct Answer: A

Rationale: The correct answer is A: Cardiac Arrest. High magnesium levels in renal failure can lead to cardiac arrest due to the inhibitory effect on neuromuscular transmission and cardiac muscle activity. Magnesium impairs calcium entry into cells, affecting muscle contraction, potentially leading to fatal arrhythmias and cardiac arrest. Respiratory paralysis (B) is unlikely as magnesium does not directly affect respiratory muscles. Liver encephalopathy (C) is unrelated to high magnesium levels. Death from hemorrhage (D) is not a typical consequence of elevated magnesium levels in renal failure.

Correct Answer: C

Rationale: The correct answer is C because target cells respond to hormones by possessing specific receptors for that hormone. These receptors bind to the hormone, initiating a cellular response. Option A is incorrect as proximity to hormone-producing cells is not the reason for response. Option B is incorrect as target cells do not make the hormones they respond to. Option D is incorrect as not all cells respond to all hormones; only target cells with specific receptors do.

Correct Answer: A

Rationale: The correct answer is A: hormonal stimulus. Endocrine organs are typically activated by other hormones circulating in the bloodstream, triggering a chain reaction of hormonal responses. This is known as hormonal stimulus. Other choices are incorrect because humoral stimulus refers to changes in blood levels of ions or nutrients, neural stimulus involves nerve impulses, and receptor-mediated stimulus is not a recognized term in endocrine physiology.

Correct Answer: B

Rationale: The correct answer is B: decreased secretion of antidiuretic hormone. When you drink a liter of water quickly, it leads to a sudden increase in blood volume and a decrease in blood osmolality. This triggers the body to reduce the secretion of antidiuretic hormone (ADH) to prevent excessive water retention and maintain proper fluid balance. ADH helps in water reabsorption in the kidneys, so decreased secretion allows for more water to be excreted through urine. The other choices are incorrect because drinking water rapidly would not directly affect oxytocin secretion.