Warning Signs of Lung Disease

Healthy Lungs

The lungs use a series of biological and mechanical barriers to keep harmful substances from entering the body. The body’s respiratory system filters out foreign matter and organisms that enter through the nose and mouth. Pollutants can be breathed or coughed out, wiped out by digestive juices or eaten by macrophages (a type of blood cell that patrols the body looking for germs).

Reviewed by: 
Review Date: 
May 27, 2015

Last Updated:
May 27, 2015