Which gland secretes two hormones, one that elevates blood glucose levels and another that decreases blood glucose levels?

Correct Answer: A

Rationale: The correct answer is A: Pancreas. The pancreas secretes insulin to decrease blood glucose levels and glucagon to elevate blood glucose levels. Insulin helps cells absorb glucose for energy, while glucagon triggers the release of stored glucose into the bloodstream. Adenohypophysis (B) secretes various hormones but not related to blood glucose regulation. Thyroid (C) secretes hormones that regulate metabolism, not directly impacting blood glucose levels. Adrenal cortex (D) secretes hormones like cortisol and aldosterone, which are not primarily involved in blood glucose regulation.

Correct Answer: C

Rationale: The correct answer is C: Cortisol. Cortisol exerts negative feedback control on the secretion of ACTH by inhibiting the release of corticotrophin-releasing hormone (CRH) and ACTH from the hypothalamus and pituitary gland, respectively. This feedback loop helps regulate the body's stress response and maintain hormone levels within a normal range. A: PTH (Parathyroid Hormone) does not directly regulate the secretion of ACTH. B: Glucagon regulates blood sugar levels and does not directly affect ACTH secretion. D: Corticotrophin-releasing hormone (CRH) is the hormone that stimulates the release of ACTH, so it does not exert negative feedback control on ACTH secretion.

Correct Answer: B

Rationale: The correct answer is B: He will develop an acute adrenal insufficiency. When a patient abruptly stops taking a large dose of prednisone after long-term use, it can suppress the body's natural production of cortisol. This sudden withdrawal can lead to adrenal insufficiency, a potentially life-threatening condition. The adrenal glands may not be able to produce enough cortisol to meet the body's needs, causing symptoms such as fatigue, weakness, low blood pressure, and even shock. This is a serious concern that requires medical attention. Incorrect choices: A: His arthritic pain will recur - While this is a valid concern, it is not the most serious issue compared to acute adrenal insufficiency. C: He will continue to exhibit symptoms of Cushing syndrome - Cushing syndrome is a result of prolonged exposure to high levels of cortisol, not sudden withdrawal. D: He will develop a moon face and buffalo hump - These are physical symptoms associated with Cushing syndrome, not acute adrenal

Correct Answer: C

Rationale: The correct answer is C: Pineal gland. The pineal gland is located in the brain and is often referred to as the "biological clock" due to its role in regulating the sleep-wake cycle through the secretion of melatonin. The posterior pituitary (choice A) is responsible for releasing hormones produced by the hypothalamus, not related to the circadian rhythm. The hypothalamus (choice B) is involved in regulating various physiological processes but is not directly associated with the circadian rhythm. The thymus (choice D) plays a role in the immune system, not in regulating the biological clock. Thus, the pineal gland is the correct answer as it specifically controls the circadian rhythm.

Correct Answer: A

Rationale: The correct answer is A: Thyroid. The thyroid gland produces thyroid hormones T3 and T4, which regulate the body's metabolic rate. These hormones control the basal metabolic rate (BMR) by influencing the rate at which cells use energy. The other choices, B: Parathyroid, C: Testes, and D: Pancreas, do not directly control BMR. Parathyroid regulates calcium levels, Testes produce hormones related to reproduction, and Pancreas regulates blood sugar levels through insulin and glucagon secretion. Thyroid is the only gland among the choices that specifically influences BMR.