What are the details of the structure of the heart?

The heart has four chambers: at the top is the right atrium and the left atrium, at the bottom is the right ventricle and the left ventricle The atria are separated from the ventricles by valves There are four main blood vessels entering and leaving the heart: the vena cava brings in deoxygenated blood from the body, the blood passes from the heart to the lungs in the pulmonary artery, in the lungs the blood collects oxygen and this oxygenated blood passes from the lungs to the heart in the pulmonary vein where the blood is then pumped from the heart to the body in the aorta