Heart Valve Information Overview
According to the American Heart Association, about 5 million Americans each year learn that they have heart valve disease, which disrupts the flow of blood through the heart.
What Are Heart Valves?
To understand the heart valves and their function, you must first know how blood flows through the chambers of the heart. Sometimes medical words can be confusing and hard to pronounce, and it is sometimes helpful to know where we get the words.
In the heart there are four chambers, and blood moves from one chamber to the next as it flows through the heart. The first chamber blood enters as it returns from the body is the right atrium. The word atrium comes from the Latin word for "entrance hall" or "reception hall" in a house.
After blood collects in the right atrium it is pumped into the right ventricle. The word ventricle comes from a Latin word which means "stomach". The ventricle is something like a stomach, collecting blood and then emptying it. Blood leaves the right ventricle and goes into the pulmonary artery which supplies the lungs. After the blood receives oxygen, it returns to the left side of the heart, the left atrium.
After collecting in the left atrium, it is pumped into the left ventricle, and from there it is pumped into the aorta, the largest blood vessel in the body. From the aorta, blood courses throughout the body through its arteries.
For blood to go in only one direction, forward, it must pass through the heart valves, which function as one-way doors, opening and shutting with each beat of the heart. Just as there are four chambers to the heart, there are four heart valves. Blood must pass through one of these valves each time it leaves a chamber.
The Four Heart Valves
- Tricuspid: The tricuspid valve is named because it has three leaflets. It is located between the right atrium and right ventricle.
- Pulmonary: The pulmonary valve is named because it is located below the pulmonary artery, between the right ventricle and the pulmonary artery.
- Mitral: The mitral valve is named because it looks like an upside down bishop's hat or mitre. It is the only heart valve with two leafets; all of the others have three. It is located between the left atrium and left ventricle.
- Aortic: The aortic valve is named because it is located below the aorta, between the left ventricle and aorta.
The two valves located between the atria and ventricles, the tricuspid and mitral valves, are known as atrioventricular valves. The two other valves, the pulmonary and aortic, are sometimes called semilunar valves, because each of those valves has leaflets that are shaped like half-moons.