Clinical Sonography III Practice Exam 2026 - Free Sonography Practice Questions and Study Guide

Papaverine is a direct vasodilator that relaxes vascular smooth muscle, leading to a larger arterial lumen. It works by increasing levels of cAMP/cGMP in smooth muscle, which reduces calcium-driven contraction and causes relaxation. The result is arterial dilation and decreased vascular resistance, improving blood flow. Veins are not the primary target in this scenario, so the main expected change is an increase in arterial diameter.