The heart has four valves: 1) the tricuspid valve is between the right atrium and right ventricle; 2) the pulmonary valve is between the right ventricle and the pulmonary artery; 3) the mitral valve is between the left atrium and left ventricle; 4) the aortic valve is between the left ventricle and the aorta.
Each valve has a set of flaps, also called cusps. When working properly, the heart valves open and close fully. Heart valves don't always work as they should. A person can be born with an abnormal heart valve, a type of congenital heart defect.