The opening between the right atrium and the right ventricle is guarded by

The opening between the right atrium and the right ventricle is guarded by a valve formed of three muscular flaps or cusps, the tricuspid valve.The bicuspid or mitral valve guards the opening between the left atrium and the left ventricle.Thebesian valve is located at the opening of the coronary sinus into the right atrium.The semilunar valves guard the  openings of the right ventricle and the left ventricle into the pulmonary artery and the aorta respectively.