Steroids:

Correct Answer: B

Rationale: The correct answer is B because steroids include glucocorticoids, mineralocorticoids, and androgens, which are hormones secreted by the adrenal cortex. Glucocorticoids regulate metabolism and immune response, mineralocorticoids regulate electrolyte balance, and androgens are male sex hormones. Choice A is incorrect because steroids are secreted by the adrenal cortex, not the adrenal medulla. Choice C is incorrect because steroids act by entering the target cells and binding to intracellular receptors, not by stimulating second messengers like cAMP. Choice D is incorrect because steroids are not secreted by the pancreas; instead, the pancreas secretes hormones like insulin and glucagon.

Correct Answer: A

Rationale: Rationale: 1. Oxytocin is a neurohypophyseal hormone secreted by the posterior pituitary gland. 2. It plays a key role in stimulating uterine contractions during labor and childbirth. 3. This action helps in the progression of labor by promoting the expulsion of the fetus. 4. Oxytocin also stimulates milk ejection during breastfeeding. 5. Choice A is correct as it accurately describes the role of oxytocin in uterine muscle contraction. Summary: B: Oxytocin is not a gonadotropin; it does not directly affect gonadal function. C: Oxytocin does not stimulate the kidney to reabsorb Na+ and water; that is the role of other hormones like aldosterone. D: Oxytocin is not a mineralocorticoid; it does not regulate electrolyte balance like mineralocorticoids do.

Correct Answer: C

Rationale: The correct answer is C: Pineal gland. The pineal gland is responsible for secreting melatonin, a hormone that regulates our biological rhythms such as sleep-wake cycles. This gland is located in the brain and plays a crucial role in maintaining our circadian rhythm. The other choices are incorrect because: A: The pancreas secretes insulin and glucagon to regulate blood sugar levels, not melatonin. B: The adenohypophysis, or anterior pituitary gland, secretes various hormones but not melatonin. D: The adrenal gland produces hormones like cortisol and adrenaline, not melatonin.

Correct Answer: D

Rationale: The correct answer is D: polyphagia. Polyphagia is the medical term for excessive eating despite adequate glucose levels in the blood, commonly seen in conditions like diabetes mellitus. This excessive hunger is due to the body's inability to use glucose effectively, leading to a constant feeling of hunger. A: Acidosis refers to an excess of acid in the blood, not related to excessive eating. B: Polyuria is excessive urination, not directly related to excessive eating. C: Polydipsia is excessive thirst, also not directly related to excessive eating. In summary, polyphagia is the correct term for excessive eating despite adequate glucose levels, while the other choices are unrelated to this specific symptom.

Correct Answer: C

Rationale: The correct answer is C: raise blood glucose levels. Glucagon, growth hormone, cortisol, and epinephrine all work together to increase blood glucose levels through various mechanisms. Glucagon stimulates the breakdown of glycogen into glucose, growth hormone promotes gluconeogenesis, cortisol increases blood sugar through gluconeogenesis and inhibiting glucose uptake, and epinephrine triggers glycogen breakdown and inhibits insulin release. Choices A, B, and D are incorrect because not all of these hormones are secreted by the adrenal gland, they do not directly expand blood volume, and they do not stimulate osteoclastic activity, respectively.