The morphologically right atrioventricular valve has three leaflets (tricuspid): septal, inferior (mural), and anterosuperior which are separated from each other by anteroseptal, superoinferior, and inferoseptal commissures, respectively. The inferior leaflet takes its origin exclusively from the diaphragmatic parietal wall of the ventricle and is often called the mural leaflet. Each commissure is usually supported by the corresponding papillary muscle. The most characteristic and distinguishing feature of the tricuspid valve is the direct attachment of the cords from the septal leaflet to the septum.