ATI RN
Endocrine System Questions and Answers PDF Questions
Question 1 of 5
The portion of the pituitary that arises from the roof of the primitive oral cavity is the:
Correct Answer: A
Rationale: The adenohypophysis (anterior pituitary) develops from Rathke's pouch, an outpocketing of the oral cavity's roof, forming glandular tissue that secretes hormones like ACTH. The neurohypophysis (posterior pituitary, including pars nervosa) and infundibulum arise from the brain's floor, neural ectoderm, storing hypothalamic hormones (e.g., ADH). Pars nervosa is a neurohypophysis subset, not distinct here. Adenohypophysis' oral origin drives its endocrine role, distinguishing it from neural-derived parts, key to pituitary embryology.
Question 2 of 5
Secretion of which hormone would be increased in an iodine-deficiency goiter?
Correct Answer: A
Rationale: In iodine-deficiency goiter, low iodine reduces thyroxine (T₄) and T₃ synthesis, prompting the pituitary to increase TSH (thyroid-stimulating hormone) to stimulate the thyroid, causing enlargement (goiter). Thyroxine and T₃ decrease due to substrate lack, not increase. 'All' is incorrect only TSH rises to compensate. TSH's feedback-driven surge distinguishes it, key to goiter pathology, unlike diminished thyroid hormones.
Question 3 of 5
Stimulation of the mother's nipples by the baby's nursing initiates sensory impulses which pass into the central nervous system and eventually reach the hypothalamus. These impulses result in the:
Correct Answer: C
Rationale: Nipple stimulation sends signals to the hypothalamus, triggering oxytocin release from the posterior pituitary for milk ejection via myoepithelial contraction. Prolactin, for milk synthesis, comes from the anterior pituitary, not posterior, and isn't 'lactogenic' specifically here. Prolactin-inhibiting factor (dopamine) suppresses prolactin, not aiding lactation. Oxytocin's ejection role distinguishes it, critical for nursing, unlike synthesis or inhibitory actions.
Question 4 of 5
An expectant mother tells the nurse that she is concerned about breastfeeding and asks the nurse how her body knows that it is time to produce milk. The nurse's best response regarding stimulus for milk production is that delivery of the fetus:
Correct Answer: A
Rationale: Delivery of the fetus triggers events increasing prolactin levels placental expulsion drops progesterone/estrogen, relieving anterior pituitary inhibition, boosting prolactin for milk synthesis. Oxytocin, also rising, aids ejection, not production. Estrogen drops post-delivery, not rapidly increasing high levels suppress lactation. Prolactin's surge, driven by hormonal shifts and suckling, distinguishes it, key to lactogenesis, unlike ejection or estrogen dynamics.
Question 5 of 5
A small molecule binds to a G protein, preventing its activation. What direct effect will this have on signaling that involves cAMP?
Correct Answer: B
Rationale: G proteins activate adenylyl cyclase in cAMP signaling, converting ATP to cAMP to amplify signals (e.g., epinephrine response). Blocking G protein prevents this activation, halting cAMP production. Hormone binding occurs upstream, excessive cAMP or phosphorylation would require activation. This inhibition distinguishes the direct effect, key to understanding second messenger disruptions in cellular signaling pathways.