What prevents the backflow of blood in heart?

The **heart valves** prevent the backflow of blood in the heart. There are four main valves: the **tricuspid**, **pulmonary**, **mitral**, and **aortic** valves. These valves act like one-way gates, opening to allow blood to flow forward and closing to stop it from moving backward. The **atrioventricular valves** (tricuspid and mitral) prevent backflow into the atria when the ventricles contract, while the **semilunar valves** (pulmonary and aortic) stop blood from returning to the ventricles after it has been pumped out. Proper valve function ensures efficient blood circulation and maintains the heart’s role as a one-way pump.