Which hormones are produced by the posterior pituitary?

Correct Answer: A

Rationale: The correct answer is A: oxytocin and antidiuretic hormone. The posterior pituitary stores and releases these hormones, which are produced in the hypothalamus. Oxytocin is involved in uterine contractions and milk ejection, while antidiuretic hormone regulates water balance. Choices B, C, and D are incorrect because human growth hormone and thyroid-stimulating hormone are produced by the anterior pituitary, prolactin and follicle-stimulating hormone are produced by the anterior pituitary, and glucocorticoids and androgens are produced by the adrenal glands, respectively.

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.

Correct Answer: D

Rationale: The correct answer is D: thymus gland. The thymus gland is crucial for the development and maturation of T cells, a type of immune cell. The hormones produced by the thymus gland, such as thymosin, play a key role in the proper functioning of the immune system. Without a functional thymus gland, the immune response would be compromised. Explanation for why other choices are incorrect: A: Adrenal medulla does not play a direct role in immune response development. B: Pancreas primarily produces hormones related to blood sugar regulation, not immune response. C: Thyroid gland produces hormones that regulate metabolism, not directly related to immune response development.