High magnification image of a plastic section through a muscular artery. The
wall of this artery is made of three concentric layers: (1) tunica
intima (innermost layer), composed of simple squamous epithelium
of endothelial cells; (2)
tunica media, consisting of the internal
elastic lamina (arrow) and 11 or more circular layers of smooth muscle
cells; (3) tunica adventitia (outermost
layer) composed of collagen fibers and connective tissue
cells.
