The Arachnoid Villi Lack the Tunica Media Found in Blood

Question

The arachnoid villi lack the tunica media found in blood vessels.

Accepted Answer

Arachnoid villi are small protrusions of the arachnoid mater (the middle layer of the meninges) into the dural venous sinuses, and they do not contain the tunica media, which is a layer of smooth muscle found in the walls of blood vessels.