Metarteriol [Et(A)- + Arteriole]

Metarteriole [et(a)- + arterioles] - see Precapillary arteriole.

Precapillary arteriole is a small artery that directly passes into a capillary. Precapillary arterioles regulate blood flow in capillary networks. Their walls contain smooth muscle cells that can contract, changing the lumen of the arteriole and regulating the blood supply to the tissues. Thus, precapillary arterioles play an important role in the local regulation of tissue blood flow.