Metarteriole

A metarteriole is a short microvessel in the microcirculation that links arterioles and capillaries. Instead of a continuous tunica media, they have individual smooth muscle cells placed a short distance apart, each forming a precapillary sphincter that encircles the entrance to that capillary bed. Constriction of these sphincters reduces or shuts off blood flow through their respective capillary beds. This allows the blood to be diverted to elsewhere in the body.

Metarteriole

A metarteriole is a short microvessel in the microcirculation that links arterioles and capillaries. Instead of a continuous tunica media, they have individual smooth muscle cells placed a short distance apart, each forming a precapillary sphincter that encircles the entrance to that capillary bed. Constriction of these sphincters reduces or shuts off blood flow through their respective capillary beds. This allows the blood to be diverted to elsewhere in the body.