Can Arterioles Constrict and Dilate?

The constriction of arterioles increases resistance, which causes a decrease in blood flow to downstream capillaries and a larger decrease in blood pressure. Dilation of arterioles causes a decrease in resistance, increasing blood flow to downstream capillaries, and a smaller decrease in blood pressure.

What causes arterioles to dilate?

Nervous stimulation and local chemical influences signal the smooth muscles of the arteriole wall. When the arterioles contract (vasoconstriction) the blood bypasses the tissues, and when they dilate (vasodilation) the blood flow in the local capillaries increases markedly.

Do arterioles dilate?

When blood vessels dilate, the flow of blood is increased due to a decrease in vascular resistance and increase in cardiac output. Therefore, dilation of arterial blood vessels (mainly the arterioles) decreases blood pressure.