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Blood Vessels in Your Heart

Like the other muscles in your body, your heart needs oxygen to live and work. The blood vessels that deliver blood to your heart muscle are the coronary arteries. They are called the coronary arteries because they encircle and sit on the surface of your heart like a crown. The word coronary means crown.

Someone you know may have coronary artery disease (CAD), or heart disease. A person with CAD has at least one coronary artery that's clogged and isn't letting all of the blood through to the heart.

Coronary Arteries That Are Commonly Blocked

The coronary arteries are divided into two systems. The left coronary artery system supplies blood mostly to the left side of your heart. The right coronary artery system supplies blood mostly to the right side of your heart.

The larger arteries in each system are the ones that are most likely to be affected by coronary artery disease (Figure 1):

Left main artery, which branches directly from the left side of the aorta
Left anterior descending artery
Left circumflex artery
Right coronary artery, which branches directly from the right side of the aorta
Posterior descending artery

Figure 1

Coronary Arteries That Are Commonly Blocked

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Coronary Veins

Like other veins in your body, coronary veins carry deoxygenated (blue) blood, or blood that has already been "used" by your body. And like coronary arteries, coronary veins work just in your heart. Coronary veins collect the oxygen-poor blood from your heart muscle—not from inside the heart chambers, but from the heart wall.

Coronary veins empty blood directly into the right atrium through the coronary sinus. The coronary sinus is a small hole in the right atrium protected by a flap of tissue (Figure 2).


Figure 2

Coronary Sinus

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Next: Blood Vessels Outside Your Heart

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Q. What is the job of your coronary arteries?

 To supply oxygen-rich blood to your heart muscle

 To carry oxygen-poor blood to your lungs