Blood flows from the inferior and superior vena cava
into the right atrium
, it then flows into the right ventricle
where it is pummped from there via pulmonary artery
so that it can pickup oxygen from the lungs then the oxygen rich blood returns through thye pulmonary vain into the left atrium. through there, it goes to the left ventricle and then to the Aorta, which distributes the blood and then the blood begins the entire process over again.