The tunica media (Neo-Latin "middle coat"), or media for short, is the middle tunica (layer) of an artery or vein. It lies between the tunica intima on the inside and the tunica externa on the outside.

Artery

The tunica media is made up of smooth muscle cells, elastic tissue and collagen. It lies between the tunica intima on the inside and the tunica externa on the outside. The middle coat (tunica media) is distinguished from the inner (tunica intima) by its color and by the transverse arrangement of its fibers.

Vein

The middle coat is composed of a thick layer of connective tissue with elastic fibers, intermixed, in some veins, with a transverse layer of muscular tissue. The white fibrous element is in considerable excess, and the elastic fibers are in much smaller proportion in the veins than in the arteries.

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