Breathing consists of two phases: inspiration (you breathe in, and air flows into the lungs) and expiration (you breathe out, and gases leave the lungs). During inspiration, the diaphragm and intercostal muscles contract allowing air to enter the lungs. During expiration, the diaphragm and intercostal muscles relax forcing gases to flow out of the lungs.
The Process of Breathing
Updated November 26, 2008
About.com Health's Disease and Condition content is reviewed by the Medical Review Board
Breathing
A.D.A.M.More About the Respiratory System
Definition of DiaphragmDefinition of NaresDefinition of Respiratory Failure
Suggested Reading
Suggested Reading
Bronchopulmonary Hygiene Causes, Symptoms and Treatment of HypercapniaPostural Drainage
See More About:
Related Articles
