Pulmonary valve

Pulmonary valve

The pulmonary valve (also known as the pulmonic valve) is one of the four valves of the heart, which stands at the opening from the right ventricle to the pulmonary artery. It is a semilunar valve, similar to the aortic valve, but differs in location and function.

Structure

The pulmonary valve is located in the heart between the right ventricle and the pulmonary artery. It is one of the two semilunar valves of the heart, the other being the aortic valve. The valve is composed of three cusps, each a half-moon shape. The cusps are thin, pliable, and strong, allowing them to open and close as the heart beats.

Function

The primary function of the pulmonary valve is to prevent backflow of blood from the pulmonary artery into the right ventricle during diastole. When the right ventricle contracts (systole), the pressure causes the valve to open, allowing blood to exit the right ventricle and enter the pulmonary artery. When the right ventricle relaxes (diastole), the pressure in the ventricle drops, causing the valve to close and preventing backflow of blood.

Clinical significance

Diseases of the pulmonary valve include pulmonary valve stenosis and pulmonary valve insufficiency. Pulmonary valve stenosis is a condition in which the flow of blood from the right ventricle to the pulmonary artery is obstructed by a narrowing of the pulmonary valve. Pulmonary valve insufficiency, also known as pulmonary regurgitation, is a condition in which the pulmonary valve does not close properly, allowing blood to flow back into the right ventricle.

See also

• Heart valve
• Pulmonary circulation
• Cardiac cycle

References

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