The tricuspid valve is one of the four main valves in the heart. It is located between the right atrium and the right ventricle, allowing blood to flow from the atrium to the ventricle while preventing backflow. The valve has three flaps, or cusps, which open and close with each heartbeat. When the right atrium fills with blood, the tricuspid valve opens to let the blood pass into the right ventricle. Once the ventricle is full, the valve closes to ensure that blood is pumped into the pulmonary artery and not back into the atrium during contraction.