
There are four valves within your heart. They are the mitral, tricuspid,
aortic and pulmonic valve. The mitral valve and tricuspid valve lie between the
atria (upper heart chambers) and the ventricles (lower heart chambers). The
aortic valve and pulmonic valve lie between the ventricles and the major blood
vessels leaving the heart. As blood leaves each chamber of the heart, it passes
through a valve. Your heart valves make sure that blood flows in only one
direction through your heart.

Mitral Valve Mouse-over image to see the mitral valve open.

How Valves Work
The right and left sides of the heart work together to pump blood
throughout the whole body. The four heart valves make sure that blood always
flows freely in a forward direction and that there is no backward leakage.

Blood flows from your right and left atria into your ventricles through the open
mitral and tricuspid valves

When the ventricles are full, the mitral and tricuspid valves shut. This
prevents blood from flowing backward into the atria while the ventricles
contract (squeeze).

As the ventricles begin to contract, the pulmonic and aortic valves are
forced open and blood is pumped out of the ventricles through the open valves
into the pulmonary artery toward the lungs, and the aorta, to the body

When the ventricles finish contracting and begin to relax, the aortic and
pulmonic valves snap shut. These valves prevent blood from flowing back into the
ventricles. This pattern is repeated, causing blood to flow continuously to the
heart, lungs and body
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