Atrioventricular Septum

The atrioventricular septum Divides the trioventricular canal. The atrioventricular endocardial cushions fuse and condense into distinct mitral and tricupsid valve primordium which remodel to form the leaflets and supporting structures. The layers in the atrioventricular valve leaflets are called the atrialis, the spongiosa and fibrosa from the atrial to the ventricular sides. The valves are primarily composed of an organized matrix of connective tissue.