How do the heart and lungs work together?

This isn't physics, it's biology but basically, when you breath in oxygen, the oxygen goes to the lungs which transfer it to the blood cells. The heart then pumps the blood cells round to the organs, muscles etc and the blood cells drop off the oxygen where necessary, they then pick up carbon dioxide and the heart pumps them to the lungs where the blood cells give the lungs the carbon dioxide and the lungs make you breath the carbon dioxide out (his is a very simplified explanation, I'm not a biologist)