Air Intake in the Lungs
The blue air in the lungs is high in Carbon Dioxide and low in Oxygen,
compared to the white outside air. Because both inspiration and expiration take place
through the same air passageways, very little of the total lung volume is exchanged in
each breath. Only about 5% of the blue air is refreshed with outside air, represented by
the lighter blue shade. The pleura sac is shown in pink.