ATI RN
Endocrine System Multiple Choice Questions Answers Questions
Question 1 of 5
Most hormones of the endocrine system are regulated by a:
Correct Answer: A
Rationale: Negative feedback regulates most hormones (e.g., cortisol inhibits ACTH), reducing secretion when levels suffice, maintaining homeostasis. Positive feedback (e.g., oxytocin in labor) amplifies, rare in endocrine control. Hormone-receptor complexes mediate effects, not regulation. Hormone-gene complexes influence steroid action, not feedback. Negative feedback's inhibitory loop distinguishes it, critical for stability, unlike amplifying or mechanistic options.
Question 2 of 5
The alpha cells of the pancreas secrete which targets the
Correct Answer: A
Rationale: Alpha cells secrete glucagon, targeting the liver to raise blood glucose via glycogenolysis and gluconeogenesis. Melatonin is pineal, calcitonin thyroid-derived, and glucagon's kidney role is secondary. Liver targeting distinguishes glucagon's function, vital for glucose homeostasis, contrasting with sleep or calcium regulators.
Question 3 of 5
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.
Question 4 of 5
The body of a squirrel has to prepare for either fighting or running away by using which of the following hormones?
Correct Answer: A
Rationale: Adrenaline, from the adrenal medulla, primes the body for 'fight or flight' by boosting heart rate, glucose release, and muscle blood flow ideal for a squirrel's rapid response. Oestrogen (ovaries) and testosterone (testes) drive reproductive traits, thyroxine (thyroid) sets metabolism not acute stress. Adrenaline's rapid, systemic effects distinguish it, key to survival in danger, contrasting with long-term hormonal actions.
Question 5 of 5
The hormone progesterone is secreted by which of the following glands?
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.