Bursae are fluid-filled cavities located at tissue sites where tendons or muscles pass over bony prominences near joints. Their function is to facilitate movement and reduce friction between moving parts. When a bursa becomes infected, traumatized, or injured it is referred to as bursitis.
Update Date 9/8/2014
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.