Pharmacology and the Nursing Process by Linda Lane Lilley: Practice Exam

How do vasodilators work to lower blood pressure?

1. By blocking adrenergic receptors

2. By causing relaxation of arteriolar and/or venous smooth muscle

3. By increasing plasma volume

4. By blocking calcium channels

The correct answer is: By causing relaxation of arteriolar and/or venous smooth muscle

Vasodilators work by causing relaxation of arteriolar and/or venous smooth muscle, allowing more blood to flow through the blood vessels, which in turn lowers blood pressure. Option A and D are incorrect because they both involve blocking, not relaxing, which is the opposite of what vasodilators do. Option C is also incorrect because increasing plasma volume would actually increase blood pressure, not lower it.