The heart has four chambers- The two upper chambers(right atrium and left atrium), receive and collect blood.
The two lower chambers (right ventricle and left ventricle), pump blood to the other parts of the body.
The left side of the heart contains oxygenated blood.
The left atrium receives oxygenated blood from the lungs through the pulmonary vein.
The left ventricle pumps oxygenated blood to different parts of the body through the aorta.