Breathing consists of two phases. The first phase is the
inspiration phase. Inspiration allows air to flow into the lungs.
The second phase is expiration. Expiration involves gases leaving
the lungs. During inspiration, the diaphragm and intercostal
muscles contract allowing air to enter the lungs. During
expiration, the inspiration muscles relax forcing gases to flow out
of the lungs.
Review Date: 01/31/2011
Reviewed By: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of
Physician Assistant Studies, University of Washington, School of
Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director,
A.D.A.M., Inc.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)
