About the Mitral Valve
The mitral valve sits between the left atrium and left ventricle, and is comprised of two leaflets, anterior and posterior. When the mitral valve is open, it allows blood to pass from the atrium to the ventricle. When closed, it prevents blood from backing up into the atrium as the ventricle pumps blood out of the heart.
Normal mitral valve leaflets are thin, delicate structures that meet each other in a process known as coaptation. The edges of the anterior and posterior leaflets are attached to the papillary muscles in the left ventricle by thin fibrous strands called the chordae tendinae. Through this attachment, the opening and closing of the mitral valve is a dynamic process guided by the motion of the left ventricle.
The mitral leaflets are anchored in the mitral annulus, which is part of the fibrous skeleton of the heart. The annulus provides the framework for the valve leaflets.