The coronary arteries deliver blood to the heart muscle, providing
a continuous supply of oxygen and nutrients needed for it to stay healthy and function
Supply and demand
arteries regulate the supply of blood to your heart muscle depending on how much oxygen
your heart needs at the time, as indicated by:
The number of times your
heart beats per minute (heart rate).
Your blood pressure.
of your heart's contractions.
The thickness of your heart muscle.
harder the heart has to work to pump blood, the more oxygen it needs. For example,
when you exercise, your heart rate and blood pressure increase, which in turn increases
your heart's demand for oxygen.
The main way to increase the oxygen supply to
the heart is to increase the blood flow through the coronary arteries. Your heart
increases the blood flow by widening (dilating) your coronary arteries.
coronary arteries aren't able to dilate properly, your heart muscle may not be able
to get the amount of oxygen it needs to function properly.
Anatomy of the coronary arteries
Your left ventricle pumps blood into the
main artery of your body, called the aorta. See a picture of the heart and coronary arteries. Close to the heart,
the two main coronary arteries branch off of your aorta.
The left main
coronary artery is a short vessel that branches into the:
Left anterior descending
artery, which supplies blood to the front (anterior wall) and part of the side (anterolateral
wall) of the left ventricle, to the top of the left ventricle, and to most of the
wall between the ventricles (interventricular septum).
which passes behind the heart between the left atrium and left ventricle and supplies
blood to the side (lateral wall) of the left ventricle. In a small number of people,
the circumflex artery supplies the lower and back portions of the left ventricle.
right coronary artery supplies blood to the right ventricle and then supplies the
underside (inferior wall) and backside (posterior wall) of the left ventricle.
What are collateral coronary arteries?
arteries also include the collateral coronary arteries, small blood vessels that connect
the normal coronary arteries with one another. When the heart is healthy, these vessels
play only a minor role. When a coronary artery becomes obstructed, though, collateral
coronary arteries help increase the flow of blood to the area of the heart that is
being deprived of blood flow. These vessels, although small, may actually succeed
in providing sufficient blood to help prevent major damage to the heart muscle during
a heart attack.
Why are my coronary arteries so
When the heart doesn't get enough oxygen-rich blood through the
coronary arteries, the affected heart muscle can weaken or die. This is what happens
during a heart attack. The damaged heart muscle cannot pump effectively, leading to
Staff Primary Medical ReviewerRakesh
K. Pai, MD - Cardiology, Electrophysiology Martin
J. Gabica, MD - Family Medicine Adam Husney, MD
- Family Medicine Specialist Medical ReviewerRobert A. Kloner, MD, PhD - Cardiology
This information does not replace the advice of a doctor.
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