Which heart valve prevents blood from returning to the right ventricle?

The heart valve that prevents blood from returning to the right ventricle is the pulmonic valve. This valve is located between the right ventricle and the pulmonary artery, which leads to the lungs. When the right ventricle contracts to pump deoxygenated blood into the pulmonary circulation, the pulmonic valve opens, allowing blood to flow out. Once the ventricle relaxes, the pulmonic valve closes to prevent the backflow of blood into the right ventricle. This ensures that blood moves efficiently toward the lungs for oxygenation without returning to the chamber from which it just exited.

In contrast, the aortic valve prevents blood from returning to the left ventricle; the mitral valve is located between the left atrium and left ventricle, controlling blood flow between these two chambers; and the tricuspid valve manages blood flow between the right atrium and right ventricle. Each of these valves plays a unique role in the cardiac cycle, maintaining proper blood flow and preventing backflow where necessary.