If you drank a liter of water very quickly, the result would be

Correct Answer: B

Rationale: Drinking a liter of water dilutes blood, lowering osmolality; negative feedback reduces ADH to excrete water, increasing urine. Oxytocin isn't involved, and increased ADH would retain water. Decreased ADH distinguishes this response, critical for fluid regulation, contrasting with retention signals.

Correct Answer: B

Rationale: Progesterone, secreted by the corpus luteum (ovarian follicle post-ovulation), sustains pregnancy by relaxing the uterus. Pituitary regulates via LH, adrenals produce cortisol, melatonin (pineal) isn't a gland here it's a hormone. Corpus luteum's temporary endocrine role distinguishes it, critical for gestation, contrasting with permanent glands or misnamed options.

Correct Answer: D

Rationale: In hypothyroidism, low T3/T4 raises TSH via negative feedback to stimulate thyroid plasma TSH is high. Glucocorticoids suppress TSH, not directly free T4. Binding proteins (e.g., TBG) rise with oestrogens (e.g., pregnancy), not hypertension total T4 rises, free stays normal. Oestrogens increase, not decrease, total T4 via TBG. High TSH distinguishes hypothyroidism's feedback loop, critical for diagnosis, unlike glucocorticoid, binding, or oestrogen effects.

Correct Answer: D

Rationale: LH (luteinizing hormone) doesn't directly raise blood sugar it stimulates gonadal hormones (e.g., testosterone). T4 boosts metabolism, mobilizing glucose. Cortisol promotes gluconeogenesis. Growth hormone counters insulin, raising glucose. LH's reproductive focus distinguishes it, lacking metabolic impact, unlike glucose-elevating hormones.

Correct Answer: D

Rationale: Thyroglobulin is synthesized in thyroid follicular cells (rough ER), secreted into colloid for iodination, not formed there key to T3/T4 production. Iodide transport is active (Na⁺/I⁻ symporter). Reverse T3 (rT3) is inert. Most T4 converts to T3 peripherally. Thyroglobulin's cellular origin distinguishes it, critical for thyroid synthesis, unlike transport, activity, or metabolism truths.