ATI RN
Endocrine System Questions and Answers PDF Questions
Question 1 of 5
When there is a marked deficiency of hormone secretion by the thyroid gland in a young child:
Correct Answer: B
Rationale: Thyroid hormone deficiency in children (e.g., congenital hypothyroidism) hinders mental and physical growth, causing cretinism stunted stature and cognition due to low metabolism. Acromegaly is GH excess, unrelated. Eye bulging (exophthalmos) ties to hyperthyroidism (Graves'). High BMR reflects hyperthyroidism, not deficiency. Growth impairment from low thyroxine distinguishes it, critical for development, unlike growth hormone or hyperthyroid effects.
Question 2 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 3 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 4 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.
Question 5 of 5
Iodide ions cross from the bloodstream into follicle cells via
Correct Answer: C
Rationale: Iodide enters thyroid follicle cells via active transport, using the sodium-iodide symporter (NIS), against its gradient, powered by sodium's electrochemical gradient. Simple diffusion lacks a carrier, facilitated diffusion doesn't use energy, and osmosis moves water. Active transport's energy dependence distinguishes it, essential for thyroid hormone synthesis, concentrating iodide for T3/T4 production.