It is made up of three cusps, anterior, posterior and septal. The septal cusp is attached to the medial margin. The anterior cusp is attached to the superior-lateral part of the margin. The posterior cusp is attached to the inferio-lateral part of the margin. The anterior cusp separates the inflow part of the right ventricle from the infundibulum.

The chordae tendinae attached to these cusps arise from  a large anterior papillary muscle, a large posterior papillary muscle and directly from the interventricular septum or from small papillary muscles attached to the septum. The chordae tendinae arising from the anterior papillary muscle are attached to the anterior and posterior cusps, those from the posterior muscle to the posterior and septal cusps and those from the septal muscles to the anterior and septal cusps.

The base of the anterior muscle is attached to the sternocostal wall of the right ventricle. The base of the posterior muscle is attached near the angle between the diaphragmatic wall and the interventricular septum. The base of the anterior papillary muscle is connected to the interventricular  septum by a special band called the  septo-marginal trabecula or the moderator band.