The close relationship and interdependence of the cardiovascular and pulmonary systems in gas exchange and transport is apparent in the anatomical design. Air is conducted down the nose, pharynx, through the larynx, down the trachea, bronchi and bronchioles and into the alveoli.

From the alveoli, oxygen diffuses into the blood while carbon dioxide diffuses out of the blood. The cardiovascular system than transports the oxygen to the whole body and transports back carbon dioxide from the tissues. The lungs acting like a pump to pump in air while the cardiac contractions pump blood (and oxygen) to the whole body.