Exploring What Is Stherosclerosis
Atherosclerosis (ath"er-o-skleh-RO'sis) comes from the Greek words
athero (meaning gruel or paste) and sclerosis (hardness). It's the
name of the process in which deposits of fatty substances,
cholesterol, cellular waste products, calcium and other substances
build up in the inner lining of an artery. This buildup is called
plaque. It usually affects large and medium-sized arteries. Some
hardening of arteries often occurs when people grow older.
Plaques can grow large enough to significantly reduce the blood's flow
through an artery. But most of the damage occurs when they become
fragile and rupture. Plaques that rupture cause blood clots to form
that can block blood flow or break off and travel to another part of
the body. If either happens and blocks a blood vessel that feeds the
heart, it causes a heart attack. If it blocks a blood vessel that
feeds the brain, it causes a stroke. And if blood supply to the arms
or legs is reduced, it can cause difficulty walking and eventually
gangrene.
How does atherosclerosis start?
Atherosclerosis is a slow, complex disease that typically starts in
childhood and often progresses when people grow older. In some people
it progresses rapidly, even in their third decade. Many scientists
think it begins with damage to the innermost layer of the artery. This
layer is called the endothelium (en"do-THE'le-um). Causes of damage to
the arterial wall include
· elevated levels of cholesterol and triglyceride (tri-GLIS'er-id) in
the blood
· high blood pressure.
· tobacco smoke
· diabetes
Tobacco smoke greatly worsens atherosclerosis and speeds its growth in
the coronary arteries, the aorta and arteries in the legs. (The
coronary arteries bring blood to the heart muscle; the aorta is the
large vessel that the heart pumps blood through to the body.)
Because of the damage to the endothelium, fats, cholesterol,
platelets, cellular waste products, calcium and other substances are
deposited in the artery wall. These may stimulate artery wall cells to
produce other substances that result in further buildup of cells.