SUSUMU NISHINAGA / SCIENCE PHOTO LIBRARY SUSUMU NISHINAGA / SCIENCE PHOTO LIBRARY
Lung alveoli. Coloured scanning electron micrograph (SEM) of alveoli (air spaces) in the lungs. Alveoli are the smallest divisions of the airways in the lungs, and are the sites of gaseous exchange. Here, oxygen is taken up by the blood from inhaled air, and carbon dioxide is released to be exhaled.
Model release not required. Property release not required.