Which of the following posterior pituitary hormones causes the kidney to decrease its excretion of urine?

Correct Answer: A

Rationale: Correct answer: A (ADH) Rationale: 1. ADH (Antidiuretic hormone) acts on the kidneys to increase water reabsorption, leading to decreased urine output. 2. ACTH (Adrenocorticotropic hormone) stimulates the adrenal glands, not the kidneys. 3. Aldosterone acts on the kidneys to regulate electrolyte balance, not directly affecting urine volume. 4. Oxytocin primarily functions in uterine contractions and milk ejection, not in kidney function.

Correct Answer: C

Rationale: The correct answer is C. The primary target of releasing and inhibiting hormones from the hypothalamus is the anterior pituitary. The hypothalamus secretes these hormones into the hypophyseal portal system, which directly connects to the anterior pituitary. This interaction controls the release of various hormones from the anterior pituitary, regulating functions such as growth, reproduction, and stress response. Choices A, B, and D are incorrect because releasing and inhibiting hormones from the hypothalamus do not primarily target the liver, adipose tissue, gonads, or bone marrow directly.

Correct Answer: B

Rationale: Calcitonin is a hormone produced by the thyroid gland. It helps regulate calcium levels in the body by inhibiting bone breakdown and lowering blood calcium levels. The thyroid gland is responsible for producing various hormones, including calcitonin. Adrenal cortex (A) produces hormones like cortisol, Pituitary gland (C) produces hormones like growth hormone, and Thymus gland (D) is involved in immune function, not hormone regulation. Therefore, the correct answer is B (Thyroid gland).

Correct Answer: B

Rationale: The correct answer is B: sweat glands. Endocrine glands secrete hormones directly into the bloodstream, affecting various organs and tissues. Sweat glands, on the other hand, are exocrine glands that release sweat through ducts onto the skin's surface to regulate body temperature. Adrenal glands produce hormones like cortisol and adrenaline (A), parathyroid glands regulate calcium levels in the body (C), and the pineal gland produces melatonin to regulate sleep-wake cycles (D). Therefore, sweat glands do not fit the definition of an endocrine gland, making them the correct choice.

Correct Answer: A

Rationale: The correct answer is A: Epinephrine & norepinephrine. These hormones are responsible for the fight-or-flight response. When facing a threat, the adrenal glands release these hormones, which increase heart rate, blood pressure, and energy levels to prepare the body to either fight or flee. Epinephrine and norepinephrine are part of the sympathetic nervous system's response to stress. Choices B, C, and D are incorrect: B: Insulin & glucagon regulate blood sugar levels, not the fight-or-flight response. C: Estrogen & progesterone are reproductive hormones, not involved in the fight-or-flight response. D: Thyroxin & melatonin regulate metabolism and sleep-wake cycles, respectively, not the fight-or-flight response.