Atherosclerosis - Topic Overview
How does atherosclerosis cause an aortic aneurysm?
Atherosclerosis is one of the major causes of
The wall of the aorta (and all blood vessels) is a dynamic tissue
made up of living cells that need nutrients and oxygen. Many of these
nutrients seep from the inside of the blood vessel through the walls to nourish
the rest of the blood vessel. When the inner lining of the vessel is covered
with an atherosclerotic plaque, nutrients can no longer seep through
sufficiently. The cells receive no oxygen, and some of them die. As the
atherosclerosis progresses and cells continue to die, the walls become weaker
At some point, a critical relationship is reached between the
pressure experienced in the center of the blood vessel, the wall tension, and
the strength of the wall itself. When this point is reached, the wall begins to
dilate (grow larger) in the area of the plaque. As the diameter of the vessel
grows, the wall tension increases, leading to even more dilation. The end
result is an aneurysm.