What is the term for medications that open blood vessels?

• A. Open blood vessels
• B. Open heart
• C. Decrease heart rate
• D. Increase platelets

Answer: (A)

Vasodilators are medications that dilate blood vessels. They work by relaxing the smooth muscle in the vessel walls, widening arteries and/or veins. This lowers systemic vascular resistance, helps reduce blood pressure, and can improve blood flow to tissues. Different vasodilators achieve this through various mechanisms—for example, some release nitric oxide to cause relaxation, others block calcium entry into smooth muscle, and others inhibit parts of the renin-angiotensin system. This term specifically describes drugs that cause vessels to open, whereas descriptions about opening the heart or increasing platelets don’t capture the vascular-widening action.