Coronary arteries and atherosclerosis

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Coronary arteries and atherosclerosis

What are coronary arteries?

Coronary arteries are blood vessels that feed oxygen-rich blood to your heart muscle.

The heart works hard to pump blood to the entire body, and it needs its own supply of blood to get the job done. Having an adequate supply of blood is important because, like the rest of your body, the heart muscle needs oxygen to stay healthy. Blood absorbs oxygen from the lungs every time you breathe, and then the heart pumps the oxygen-rich blood throughout the body. The heart pumps some of that oxygen-rich blood through the coronary arteries back to its own muscle.

How does atherosclerosis affect my coronary arteries?

When the heart muscle has to work harder, such as during exercise, it requires more oxygen. To meet this demand, the coronary arteries expand (dilate), increasing blood flow and oxygen to the heart.

In coronary artery disease (CAD), plaque builds up (atherosclerosis) on the inside walls of the coronary arteries. Plaque is made up largely of cholesterol and other fats. People who smoke or have diabetes, high cholesterol, or high blood pressure tend to build up more plaque than those who do not have these risk factors. Over time, the plaque buildup on the inside of the walls narrows the stream of blood and can restrict the artery's ability to dilate.

When the coronary arteries become narrowed by atherosclerosis, the heart can no longer regulate the amount of blood flow that it receives. The heart muscle may be able to get enough oxygen while you are at rest, but it may not be able to keep up with increased oxygen demands during exercise. As a result, the heart does not get enough oxygen, which often causes chest pain (angina).

Credits

Last updated:	May 29, 2007
Author:	Robin Parks, MS
Reviewed By:	Caroline S. Rhoads, MD - Internal Medicine, Ruth Schneider, MPH, RD - Diet and Nutrition
Editors:	Kathleen M. Ariss, MS, Pat Truman