A synovial bursa (plural bursae or bursas) is a small fluid-filled sac lined by synovial membrane with an inner capillary layer of viscous synovial fluid (similar in consistency to that of a raw egg white). It provides a cushion between bones and tendons and/or muscles around a joint. This helps to reduce friction between the bones and allows free movement. Bursae are found around most major joints of the body.

Synovial bursa
Typical joint
Prepatellar bursa.png
Within the knee joint: bursae visible top right, middle right and bottom right
Latinbursa synovialis
Anatomical terminology


There are four types of bursa: adventitious, subcutaneous, synovial, and sub-muscular. Among these, only adventitious is non-native. When any surface of the body is subjected to repeated stress, an adventitious bursa develops under it. Examples are Students' elbow and bunion.

Clinical significanceEdit

Infection or irritation of a bursa leads to bursitis (inflammation of a bursa). The general term for disease of bursae is "bursopathy."



Bursa is Medieval Latin for "purse", so named for the resemblance of an anatomical bursa to a purse. Bursae or bursas is its plural form.

See alsoEdit

External linksEdit

  • Hirji, Zameer; Hunjun, Jaspal S; Choudur, Hema N (2 May 2011). "Imaging of the Bursae". Journal of Clinical Imaging Science. 1: 22. doi:10.4103/2156-7514.80374. PMC 3177464. PMID 21966619.
  • Bursa
  • Diagram of elbow with olecranon bursa