Four valves regulate blood flow through your heart:
The tricuspid valve regulates blood flow between the right atrium and right ventricle.
The pulmonary valve controls blood flow from the right ventricle into the pulmonary arteries, which carry blood to your lungs to pick up oxygen.
The mitral valve lets oxygen-rich blood from your lungs pass from the left atrium into the left ventricle.
The aortic valve opens the way for oxygen-rich blood to pass from the left ventricle into the aorta, your body's largest artery, where it is delivered to the rest of the body