The main function of heart valves is to allow one-way flow of blood circulation in the body, allowing blood to flow from the atria to the ventricles and from the ventricles to the arteries, acting as one-way valves. Heart valves are valves within the heart. There are four valves in the heart: the aortic valve, the pulmonary valve, the mitral valve, and the tricuspid valve. During ventricular diastole, the mitral valve has to open and the arterial valve has to close to pump blood from the atria into the ventricles to avoid arterial blood returning to the ventricles. Arterial blood is exchanged within the tissues and organs to bring nutrients and oxygen to the tissues and organs, and the metabolic wastes produced by the tissues and organs are returned to the venous blood, which circulates through the bloodstream to maintain the body’s functioning. Heart valves are also an important presence in the human body, and it is recommended that you visit a hospital promptly if you experience discomfort.