Is the morphologically right atrioventricular valve tricuspid?

Abstract

The eccentric placement of the anterior papillary muscle causes the leaflets to close with three lines of apposition, and this makes the valve readily distinguishable from its mitral partner. When present, extra "scallops" in the structure of the right atrioventricular valve merely allow better coaption of the leaflets. So, although the term "cusp" is less than adequate as the descriptive basis for the structure of an atrioventricular valve, the right atrioventricular valve should still be considered to be tricuspid.