Anatomy of heart valves
There are four chambers in the human heart. The upper two chambers are called the right and left atria. The lower two chambers are called the right and left ventricles. Blood circulates between the chambers through four heart valves. The valves open and close, allowing blood to flow in only one direction.
The valves of your heart are shown in the diagram below. The valve names are: pulmonary valve, aortic valve, tricuspid valve, and mitral valve.
What functions do your heart valves perform?
Again, it should be noted that heart valves allow blood to flow in one direction in your heart. Your heart valves open to let blood flow and then close to keep blood from flowing back.
When working properly, your heart valves open and close completely. In this way, blood always moves in the same direction.
Each of the four valves of the heart can be grouped according to its function:
- The atrioventricular valves control blood flow between the upper and lower chambers of the heart. The valve between the right atrium and the right ventricle is called the tricuspid valve. The valve between the left atrium and the left ventricle is called the mitral valve.
- The semi-lunar (sickle-shaped) valves control the outflow of blood from the heart. Blood flows from the right ventricle through the pulmonary valve to the lungs, and from the left ventricle through the aortic valve to the rest of the body.
Heart valve defects and diseases
Like all physical objects in life-your computer, your car, your heart valves can have problems. Sometimes a person can be born with an abnormal heart valve, known as a congenital heart defect. The most common form of congenital heart defect is a bicuspid aortic valve. Other people may experience valve damage due to infection, rheumatic fever, calcification, and age-related changes.
Most problems with valve damage are related to the opening and closing of the valve leaflets. If the valve does not open fully, a small amount of blood will pass into the adjacent chamber - then there are signs of valve stenosis. If the valve is not closed tightly, blood may leak back out, leading to symptoms of valve insufficiency.
When these defects occur, the heart must work harder to pump the same volume of blood. Alternatively, blood is returned to the lungs or body because the blood inside the heart is not moving properly. Fluid retention and stasis occur in the vessels of the small circulatory system (lungs) and the vessels of the large circulatory system (other parts of the body).
Opening problems - Constriction (stenosis). Narrowing of the valve lumen occurs when the valve flaps do not fully open. The flaps of the valve may be hardened due to calcium deposition or scarring. As a result, it may be difficult to open the valve. In this case blood has to flow through a smaller orifice. Therefore, less blood enters the next chamber through the valve. At the same time, the heart muscle works harder, trying to push blood through the smaller opening, and the heart's need for oxygen increases. Aortic stenosis is the most common form of stenosis. Read more in our article Mitral stenosis.
Closure problems - Valve insufficiency (regurgitation). There may be several reasons for valve flaps not closing tightly. The valve's supporting elements (valve chords) may be torn or weakened, and the valve flaps themselves may be dilated and distended. At this point, blood flows back into the heart cavity through the flaps of this valve. As a result, the heart works harder to pump more blood. Mitral insufficiency is the most common form of valve malformation. Read more in our articles "Mitral Insufficiency," "Mitral Valve Prolapse," and "Barlow's Disease".