Bursae and synovial sheaths

Synovial bursae and sheaths are specialized connective tissue structures, primarily found in areas of intense mechanical friction between mobile parts of the body such as tendons, muscles, bones, or skin. Their main role is to facilitate the sliding of these structures over one another by reducing friction, excessive pressure, and wear of soft tissues. They are especially numerous around joints subjected to complex and repetitive movements, particularly in the limbs of domestic animals.

Synovial bursae (or bursae synoviales) are small, flat cavities filled with synovial fluid, interposed between moving surfaces such as a tendon and a bone. They can be classified as superficial bursae (between the skin and a bone or tendon) and deep bursae (between tendons and bones, or between muscles).

Synovial sheaths (or vagina synovialis) partially or completely enclose tendons, especially where these tendons pass through osteofibrous canals. They consist of two layers: a visceral layer (in contact with the tendon) and a parietal layer (adherent to the wall of the canal), between which synovial fluid circulates, allowing optimal gliding.