A client has been prescribed a drug that is classified as a beta-adrenergic blocker for control of hypertension. Recalling the underlying physiology, the nurse is aware that this drug functions by blocking the action of which neurotransmitter?

Correct Answer: D

Rationale: Beta-adrenergic blockers inhibit norepinephrine (and epinephrine) at beta receptors (e.g., β₁ in heart), reducing BP. Acetylcholine is cholinergic, serotonin/GABA are CNS transmitters.

Correct Answer: C

Rationale: White matter in the CNS consists of myelinated axons organized into tracts that carry signals between regions. It is not always deep to gray matter (e.g., cerebral cortex has superficial gray matter), it is myelinated (not unmyelinated), and it includes both sensory and motor fibers, not just sensory.

Correct Answer: A

Rationale: The frontal lobe handles motor functions and planning, not sensory interpretation (done by the parietal lobe’s somatosensory cortex). Parietal does somatesthetic interpretation, occipital manages vision, and temporal handles memory and audition.

Correct Answer: A

Rationale: The hypothalamus regulates body temperature, thirst (via osmoreceptors), and sleep-wake cycles. The pons and medulla handle respiration, the pituitary gland releases hormones, and the cerebrum manages higher functions.

Correct Answer: D

Rationale: All statements are correct: the medulla has decussating fibers (e.g., pyramids), is part of the reticular formation, contains cranial nerve nuclei (e.g., IX, X), and regulates heart rate, blood pressure, and breathing.