the disk in the fundus of the eye marking the point at which the optic nerve enters; it is accompanied by blood vessels, is oval, light in color and the blind spot of the retina.
ARTERIOLES. In arterioles, the tunica intima consists of a continuous endothelium and a very thin subendothelial layer. In addition, a thin, fenestrated internal elastic lamina is present in larger arterioles but absent in terminal arterioles. Generally, the tunica media consists of 2 layers of smooth muscle cells.
Elastic fibers include elastin, elaunin and oxytalan. Elastic tissue is classified as connective tissue proper. The elastic fiber is formed from the elastic microfibril (consisting of numerous proteins such as microfibrillar-associated glycoproteins, fibrillin, fibullin, and the elastin receptor) and amorphous elastin.