Three papillary muscles in the right ventricle correspond to the cusps of the tricuspid valve:

1. The anterior papillary muscle, the largest and most prominent of the three, arises from the anterior wall of the right ventricle; its tendinous cords attach to the anterior and posterior cusps of the tricuspid valve.

2. The posterior papillary muscle, smaller than the anterior muscle, may consist of several parts; it arises from the inferior wall of the right ventricle, and its tendinous cords attach to the posterior and septal cusps of the tricuspid valve.