Internal elastic lamina

The internal elastic lamina or internal elastic lamella is a layer of elastic tissue that forms the outermost part of the tunica intima of blood vessels. It separates tunica intima from tunica media.

It is readily visualized with light microscropy in sections of muscular arteries, where it is thick and prominent, and arterioles, where it is slightly less prominent and often incomplete. It is very thin in veins and venules. In elastic arteries such as the aorta, which have very regular elastic laminae between layers of smooth muscle cells in their tunica media, the internal elastic lamina is approximately the same thickness as the other elastic laminae that are normally present.

There is small amount of subendothelial connective tissue between basement membrane of endothelial cells and internal elastic lamina.

Reduplication of internal elastic lamina can be seen in elderly individuals due to intimal fibroplasia, which is part of the aging process.

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