Deoxygenated blood comes from lungs to the heart and goes through the pulmonary veins.Then it goes to the left atrium and through the bicuspid or mitral valve to the left ventricle. Then it goes to the aortic valve and to the aorta. Through the side aorta to the rest of the body.Then it comes back from the body and comes to the superior and inferior vana cava. Now it goes to the right atrium through the tricuspid valve.Then it goes back to the left ventricle, and then it goes through the polmonary valve to the to the lungs. And this repeats itself
The blood changes as one size is deoxgenated and the other is not as one goes to the lungs one comes from the lungs one goes to the heart and one goes from the heart
