Which valve has three flaps and prevents backflow from the right ventricle to the right atrium?

• A. Semilunar Valve
• B. Tricuspid Valve
• C. Pulmonary Valve
• D. Mitral Valve

Answer: (B)

Valves in the heart ensure one-way blood flow, and the valve between the right atrium and right ventricle has three leaflets, called the tricuspid valve. Its three cusps open to let blood move from the right atrium into the right ventricle, and close during ventricular contraction to prevent backflow into the atrium. The chordae tendineae and papillary muscles help hold these leaflets closed when the ventricle contracts, preventing prolapse. While another valve known as the pulmonary valve also has three cusps, its job is to prevent blood from flowing back from the pulmonary artery into the right ventricle, not to stop backflow into the right atrium. The mitral valve, by contrast, sits on the left side with two leaflets between the left atrium and left ventricle.