500
Trace the blood throughout the heart and back
superior/inferior vena cavae, r atrium, tricuspid, r ventricle, pulmonary semi lunar, p artery, lungs, p veins, L atrium, bicuspid, L ventricle, aortic semi lunar, aorta, aortic arch, descending aorta, arteries, arterioles, capillaries, venules, veins, superior/inferior vena cavae