Heart Valve.
As explained in chambers of the heart, the heart is made up of four chambers and four valves. Each heart valve plays a vital role in maintaining the correct sequence of blood flow through the heart in order that circulation of blood in the body be maintained.
Valves of the Heart.
There are four valves in the heart, each as important as the other.
- Two Atriovenricular valves and
- Two Semilunar valves.
The Two Atrioventricular Valves (AV Valves).
These are small valves which are present between the atria (upper chambers of the heart) and the ventricles (lower chambers of the heart), one on each side. They prevent the back flow of blood from the ventricles into the atria during systole (contraction of ventricles). These valves are anchored to the walls of the ventricles by chordae tendinea which are cord-like tendons and which attach the AV valves to the papillary muscles of the ventricles in a tension which prevents the AV valves from prolapsing into the atrium.
There are two papillary muscles in the left ventricle and three in the right ventricle. It is the contraction of these muscles which prevent the AV valves from prolapsing into the atria when the ventricles contract. The papillary muscles and the chordae tendinae together form the subvalvular apparatus.
The two AV valves are
- The Mitral Valve or the Bicuspid Valve is in the left side of the heart guarding the opening between the left atrium and the left ventricle.
- The Tricuspid Valve is in the right side of the heart guarding the opening between the right atrium and the right ventricle.
The Mitral Valve.
The mitral valve or the bicuspid valve is situated between the left atrium and the left ventricle in the left side of the heart. It is a non return valve which opens when the left atrium contracts to enable the blood to flow into the left ventricle, but closes when the left ventricle is full and about to contract in order to prevent back flow of blood back into the left atrium. It is made up of two leaflets or flaps.
The Tricuspid Valve.
The tricuspid valve is so called because it has three leaflets or flaps which are also called cusps. The tricuspid valve or the right atrioventricular valve is situated between the right atrium and the right ventricle. However at times, it may also have two or four cusps. It is a non return valve and allows blood to flow from the right atrium to the right ventricle only. It shuts when the right ventricle contracts so that blood flows into the pulmonary artery and not back into the right atrium.
Page 1 Page 2
Page 1 of 2
Your action step.
If you feel this article could be useful, do share it on social media and pass a comment below.
Medic On WebRelated posts: