NUR 600 Advanced Clinical Pharmacology Therapeutic Categories and Systems Exam with Questions and Answers

It covers key domains which include; Autonomic Nervous System Agents, Central Nervous System (CNS) Pharmacology, Cardiovascular Pharmacology, Endocrine Pharmacology, Infectious Disease Pharmacology, Respiratory Pharmacology and Gastrointestinal Pharmacology. A patient with symptomatic bradycardia is administered atropine. Which mechanism best explains the increase in heart rate observed? a. Activation of β1 receptors in the sinoatrial node b. Inhibition of acetylcholine release from presynaptic neurons c. Blockade of muscarinic M2 receptors in the heart d. Stimulation of nicotinic receptors in autonomic ganglia Correct Answer: c. Blockade of muscarinic M2 receptors in the heart Rationale: Atropine is a competitive antagonist of muscarinic receptors, particularly M2 receptors in the heart. By blocking parasympathetic (vagal) influence, it removes inhibitory tone on the sinoatrial node, leading to increased heart rate. It does not directly stimulate β1 receptors or nicotinic receptors. A patient receiving phenylephrine for hypotension develops reflex bradycardia. What is the most likely explanation for this response? a. Direct stimulation of cardiac β2 receptors b. Increased vagal tone due to baroreceptor activation c. Inhibition of norepinephrine reuptake d. Activation of central α2 receptors Correct Answer: b. Increased vagal tone due to baroreceptor activation Rationale: Phenylephrine is a selective α1 agonist that causes vasoconstriction and increased blood pressure. This triggers baroreceptors, leading to a reflex increase in vagal (parasympathetic) tone, which slows the heart rate.