What type of blood vessels does Hydralazine primarily dilate?

Hydralazine primarily acts as a vasodilator by specifically targeting the arterial system. Its mechanism of action involves relaxing smooth muscle in the arterial walls, which leads to a decrease in systemic vascular resistance and subsequently lowers blood pressure. This selective dilation of arteries helps to reduce the workload on the heart, making hydralazine particularly effective for treating conditions like hypertension and heart failure.

In contrast, other types of blood vessels, such as veins and capillaries, are not primarily influenced by hydralazine's effects. Veins play a vital role in blood return to the heart, and their dilation generally affects preload more than afterload, which is not the primary effect of hydralazine. Additionally, capillary dilation does not pertain to the action of hydralazine, as it primarily influences arteries. Therefore, the correct understanding is that hydralazine specifically dilates arteries, which is key to its therapeutic effects in critical care situations.