What is the primary function of the heart valves during the cardiac cycle?

The primary function of the heart valves during the cardiac cycle is to direct blood flow in one direction. The heart has four main valves: the tricuspid and mitral (or bicuspid) valves, which are located between the atria and ventricles, and the pulmonary and aortic valves, which are located at the exits of the ventricles. These valves open and close in response to pressure changes within the heart chambers, allowing blood to flow from the atria into the ventricles and from the ventricles into the arteries without allowing any backflow.

This unidirectional flow is crucial for the efficient functioning of the heart as it prevents the mixing of oxygenated and deoxygenated blood and ensures that the heart pumps effectively with each contraction. The proper functioning of the valves is essential for maintaining a coordinated and effective cardiac cycle, contributing to the overall efficiency of the cardiovascular system.