Animated scientific diagrams show how oxygen is carried to cells in the human body (and carbon dioxide is carried away) through blood vessels, and how blood is pumped by the heart and purifi... Read allAnimated scientific diagrams show how oxygen is carried to cells in the human body (and carbon dioxide is carried away) through blood vessels, and how blood is pumped by the heart and purified by the lungs.Animated scientific diagrams show how oxygen is carried to cells in the human body (and carbon dioxide is carried away) through blood vessels, and how blood is pumped by the heart and purified by the lungs.