The heart has 4 chambers in it.
Valves control the flow of blood between the atria and ventricles.
It is made up of two small doors or leaflets that come from each side of the valve and meet in the middle. Its job is to keep blood from moving back into the left atrium. The valve opens to let blood flow into the ventricle, It closes to keep blood in the ventricle until it is pushed out into the circulatory system. Mitral valve prolapse occurs when one or both of the leaflets of the valve bulge backward into the atrium as the ventricle is pushing blood out of the heart. This is not normal.