Which structure prevents backflow into the right atrium?

The tricuspid valve plays a crucial role in the heart's function by preventing the backflow of blood into the right atrium. This valve is located between the right atrium and the right ventricle and is designed to open when the right atrium contracts, allowing blood to flow into the right ventricle. When the right ventricle contracts, the tricuspid valve closes tightly, ensuring that blood is directed into the pulmonary artery and preventing any reverse flow back into the right atrium. This one-way flow is vital for maintaining effective circulation and ensuring that deoxygenated blood is efficiently sent to the lungs for oxygenation, supporting the overall functioning of the heart and the circulatory system.