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.
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.