The valves of the heart serve the cardiovascular system by controlling the direction of the blood flow during circulation and determining the exact moment in which the blood passes between the chambers of the heart as well as in and out of it entirely. In this tutorial, we will specifically explore the anatomy, function, and area of the mitral valve or bicuspid valve.
The mitral valve is one of two atrial ventricular valves. Its name comes from the fact that it is comprised of two cusps which, together, look like a bishop’s hat, called a miter. It is situated between the left atrium and the left ventricle.
The atrioventricular valves attach to the ventricular walls via the chordae tendineae which in turn attach to the papillary muscles so that the cusps are held tense and don’t invert into the atria. This extended attachment of the chordae tendineae and the papillary muscles is known as the subvalvular apparatus.
The mitral valve has an anterior and a posterior cusp. The cusps are named according to their position on the individual valve. So when referring to the cusps, it’s important to identify which valve it belongs to.
The valves of the heart control the blood flow in and out of the heart, specifically the atrioventricular valves function to prevent the backflow of blood from the ventricles to the atria during cardiac systole.
Opening and closing of the valves is governed by the gradient pressure across the valves themselves, and the first heart sound can be heard when the atrial ventricular valves close. When you here the classic “lub-dub” sound the heart makes, the mitral valve is contributing to the “lub” sound.