Which heart valve prevents backflow from the right ventricle into the right atrium?

• A. Pulmonary valve
• B. Aortic valve
• C. Tricuspid valve
• D. Mitral valve

Answer: (C)

Valves keep blood moving in one direction by opening and closing with pressure changes in the heart. The valve between the right atrium and the right ventricle is the tricuspid valve. It opens to allow blood to move from the atrium into the ventricle during relaxation, and it closes as the right ventricle contracts. That closing prevents backflow of blood into the right atrium during systole, which is crucial for maintaining forward flow.

The tricuspid valve is supported by structures called the chordae tendineae and papillary muscles, which help prevent the valve from bulging backward into the atrium when the ventricle squeezes.

For context, other valves are located at different outlet points: the pulmonary valve sits between the right ventricle and the pulmonary artery, preventing backflow into the ventricle; the mitral valve sits between the left atrium and left ventricle; and the aortic valve sits between the left ventricle and the aorta.