The Respiratory System - How the Lungs Work

Macrophages are white blood cells that clean the lungs.

Credits

Alvi the Alveolus appears courtesy of the American Lung Association in Wisconsin.

All other illustrations by Tom Rolain, Medical Illustrator.

Text and character poems written by Tom Rolain.

Photo micrographs of lung tissue and photograph of the resin cast of the human lungs scanned and colorized from
"The Pathway for Oxygen" by Ewald R. Weibel, M.D.

Electron micrographs of lung tissue and macrophage scanned and colorized from
"Tissues and Organs: a text atlas of scanning electron microscopy" by Richard G. Kessel and Randy H. Kardon

Photographs of lung tissue (healthy and smoking) from the University of Wisconsin-Madison medical photographs archive.