In the inflow and outflow area of the heart chambers there are valves which prevent the blood from flowing back in the wrong direction. Each heart half has a sail valve and a pocket valve: 1. Tricuspid valve (between the right atrium and right ventricle) 2. Pulmonary valve (between the right ventricle and pulmonary artery) 3. Mitral valve (between the left atrium and left ventricle) 4. Aortic valve (between the left ventricle and the aorta).
