ATI RN
Endocrine System Questions Questions
Question 1 of 5
The primary method of control of the endocrine system is negative feedback. Which of the following best describes negative feedback?
Correct Answer: C
Rationale: Negative feedback in the endocrine system adjusts hormone levels inversely: low T₃ and T₄ (thyroid hormones) signal the pituitary to increase TSH, stimulating thyroid output to restore levels. High T₃/T₄ would decrease TSH, not increase, opposing feedback's corrective nature. Low T₃/T₄ decreasing TSH would worsen deficiency, defying regulation. No effect ignores feedback entirely TSH rises to compensate. This inverse response exemplifies negative feedback, distinguishing it, essential for homeostasis, unlike positive or null reactions.
Question 2 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 3 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 4 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.
Question 5 of 5
If an autoimmune disorder targets the alpha cells, production of which hormone would be directly affected?
Correct Answer: D
Rationale: Alpha cells in the pancreatic islets produce glucagon, raising blood glucose via glycogenolysis. An autoimmune attack on them directly reduces glucagon. Somatostatin, from delta cells, inhibits other hormones. Pancreatic polypeptide, from PP cells, regulates digestion. Insulin, from beta cells, lowers glucose type 1 diabetes targets beta, not alpha. Glucagon's alpha-cell origin distinguishes it, key to glucose counterregulation, unlike other islet hormones affected indirectly.