One of the many effects that NO has on the body is vasodilation, thereby __________.

One of the many effects that NO has on the body is vasodilation, thereby __________.

• A. Decreasing blood pressure
• B. Increasing heart rate
• C. Causing inflammation
• D. Reducing respiratory rate

Answer: (A)

Nitric oxide is a potent vasodilator released by endothelial cells. It diffuses into vascular smooth muscle and activates soluble guanylate cyclase, increasing cGMP, which causes the smooth muscle to relax and the vessels to widen. This vasodilation decreases systemic vascular resistance, leading to a drop in blood pressure. The other options aren’t direct effects of NO’s action on the vessels: while a slower blood pressure could provoke a compensatory heart rate increase, that is a secondary response rather than the primary outcome of NO-driven vasodilation; NO’s role in inflammation or respiratory rate isn’t the immediate consequence described here.

Nitric oxide is a potent vasodilator released by endothelial cells. It diffuses into vascular smooth muscle and activates soluble guanylate cyclase, increasing cGMP, which causes the smooth muscle to relax and the vessels to widen. This vasodilation decreases systemic vascular resistance, leading to a drop in blood pressure. The other options aren’t direct effects of NO’s action on the vessels: while a slower blood pressure could provoke a compensatory heart rate increase, that is a secondary response rather than the primary outcome of NO-driven vasodilation; NO’s role in inflammation or respiratory rate isn’t the immediate consequence described here.