The inner layer, or tunica interna, is a thin layer only a few cells thick. It is sometimes referred to as the intima membrane. It is this layer that gives smoothness to the lining of the vessel, enhancing ~blood~ flow. It is through this tunica interna that nutrients reach the deeper parts of the media. With the passage of time the tunica interna of major arteries become coated with atheromatous plaques. These plaque deposits vary in size and shape. At a relatively early stage, these plaques consist of little lumps or nodules of scar tissue in the tunica interna. In the center of each nodule is a small cavity containing a yellowish, soft material known as ~cholesterol~. Over time, the nodules may enlarge and protrude into the |artery| increasing the risk of total blockage of the vital |artery| (thrombosis). Atheromatous deposits also weaken the walls of the arteries causing them to bulge (aneurysm) and eventually rupture.
