Bursae are similar to tendon sheaths and the he synovial membranes of joints and are subject to the same disturbances:(1)acute or chronic trauma,(2) acute or chronic pyogenic化脓性 infection,and(3) low-grade inflammatory conditions such as gout, syphilis tuberculosis or rheumatoid arthritis Two types of bursae: normally present(as over the patella and olecranon) and adventitious ones(such as develop over a bunion 姆囊炎, an osteochondroma'骨 软骨瘤, or kyphosis背 of the spine). Adventitious bursae are produced by repeated trauma or constant friction摩擦 or pressure◼ Bursae are similar to tendon sheaths and the synovial membranes of joints and are subject to the same disturbances: (1) acute or chronic trauma, (2) acute or chronic pyogenic化脓性 infection, and (3) low-grade inflammatory conditions such as gout, syphilis, tuberculosis, or rheumatoid arthritis. ◼ Two types of bursae: normally present (as over the patella and olecranon) and adventitious ones (such as develop over a bunion姆囊炎, an osteochondroma骨 软骨瘤, or kyphosis驼背 of the spine). Adventitious bursae are produced by repeated trauma or constant friction摩擦 or pressure