The ribs are the skeletal protection for the lungs and the chest cavity. The ribs and rib muscles expand and contract with normal breathing.
Update Date 11/26/2014
Updated by: C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.