So blood let’s say starts in the left atrium where it goes down through the mitral valve into the left ventricle. From the left ventricle of the blood is pushed through the aorta and from there through the various branches of the body eventually allowing oxygen rich blood to flow all across the body. Once this blood is picked up by veins as deoxygenated blood it goes back to the heart through the inferior and superior vena cava. From there the deoxygenated blood is sent into the right atrium, through the tricuspid vale into the right ventricle, through the pulmonic valve into the pulmonary artery and into the lungs for re-oxygenation. The re-oxygenated blood (oxygen rich blood) now goes through the pulmonary veins into the left atrium and the cycle beings again.
Remember this, Left side of heart is for oxygenated blood, Right side of heart is for deoxygenated blood.
Artery takes oxygen rich blood away from heart itself Vein takes oxygen poor blood back into the heart
Exceptions, Pulmonary Artery takes oxygen poor blood away from heart and into lungs
Pulmonary vein takes oxygen rich blood into the left atrium to be pushed to the rest of e body.
