ATI RN
Endocrine System Questions Questions
Question 1 of 5
A hormone may, through negative feedback, shut off the secretion of an anterior pituitary hormone by:
Correct Answer: C
Rationale: Negative feedback, like cortisol inhibiting ACTH, works by reducing hypothalamic releasing factor (e.g., CRH) secretion, decreasing pituitary output. Stimulating releasing factors increases pituitary hormones, opposite to feedback. Inhibiting an inhibiting factor (e.g., dopamine for prolactin) raises secretion, not shuts it off. 'All' overcomplicates only releasing factor inhibition fits most (e.g., TSH, ACTH). This mechanism distinguishes it, key to endocrine regulation, unlike stimulatory or mixed effects.
Question 2 of 5
A newly developed pesticide has been observed to bind to an intracellular hormone receptor. If ingested, residue from this pesticide could disrupt levels of
Correct Answer: B
Rationale: Intracellular hormone receptors, typically in the nucleus or cytoplasm, bind steroid or thyroid hormones, which cross membranes due to lipid solubility. Thyroid hormone (T3/T4) uses such receptors to regulate metabolism. Melatonin, growth hormone, and insulin act via membrane receptors, not intracellular ones. Pesticide binding could mimic or block thyroid hormone, disrupting metabolic balance, distinguishing it as the likely target, critical for endocrine disruption studies.
Question 3 of 5
The development of a goiter indicates that
Correct Answer: C
Rationale: A goiter, thyroid enlargement, often results from excessive colloid (thyroglobulin storage) accumulation, typically from iodine deficiency or TSH overstimulation, impairing hormone synthesis. Pituitary enlargement or growth hormone excess (acromegaly) don't cause goiters, nor does follicle hypertrophy alone. Colloid buildup distinguishes goiter pathology, key to diagnosing thyroid dysfunction.
Question 4 of 5
The production of melatonin is inhibited by
Correct Answer: B
Rationale: Melatonin production by pinealocytes rises in darkness and is inhibited by bright light, detected by retinal-suprachiasmatic pathways, suppressing synthesis. Declining light boosts it, serotonin is a precursor (not inhibitor), and pinealocyte activity drives production. Light's inhibitory effect distinguishes melatonin regulation, key to sleep timing, contrasting with darkness-driven increase.
Question 5 of 5
Hormones produced by the thymus play a role in the
Correct Answer: A
Rationale: Failed to generate a rationale of 500+ characters after 5 retries.