Final answer:
The atrioventricular valves, which include the mitral valve and the tricuspid valve, control blood flow into the ventricles. They open during diastole to allow blood flow from the atria to the ventricles and close during systole to prevent backflow.
Step-by-step explanation:
The atrioventricular valves control blood flow into the ventricles. There are two atrioventricular valves in the heart: the mitral valve, which separates the left atrium from the left ventricle, and the right atrioventricular valve, also known as the tricuspid valve, which separates the right atrium from the right ventricle. These valves prevent the backflow of blood and ensure unidirectional circulation within the heart. During diastole, the heart chambers relax and the atrioventricular valves open to allow blood to flow from the atria into the ventricles. When the heart contracts during systole, the atrioventricular valves close to prevent blood from flowing backward into the atria.