Blood Flows from the body into the IVC and SVC into the right atrium, then through the Tricuspid valve into the right ventricle, then through the pulmonary SL valve into the pulmonary trunk, into the right and left pulmonary arteries. The arteries take the blood to the right and left lung where it gets oxygenated, leaves the right and left lungs through the right and left pulmonary veins, into the left atrium, through the mitral (bicuspid) valve, into the left ventricle, where it goes through the aoritc SL valve, into the aorta and out to the body.