The heart is divided into the right and the left half. Both halfs are divided into an artrium and a ventricle.The right half gets de-oxygenated blood from the body via the vena cava. The atrium and the ventricle is divided by the tricuspid valve.The blood leaves the right half through the pulmonary artery. The left half gets oxygenated blood from the lung via the pulmonary vein. The atrium and the ventricle is divided by the mitral valve.The blood leaves the left half through the aorta.