Tricuspid Valve

The "atrioventricular" opening between the right atrium and the right ventricle is guarded by a large "tricuspid valve," which is composed of three leaflets or "cusps." This valve permits blood to move from the right atrium into the right ventricle and prevents it from moving back the other way. The cusps fold out of the way when the blood pressure is greater on the atrium side, and they close when the pressure is greater on the ventricular side.