Also found in: Dictionary, Thesaurus, Encyclopedia.


 [bur´sah] (pl. bur´sae) (L.)
a small fluid-filled sac or saclike cavity situated in places in tissues where friction would otherwise occur. adj., adj bur´sal. Bursae function to facilitate the gliding of muscles or tendons over bony or ligamentous surfaces. They are numerous and are found throughout the body; the most important are located at the shoulder, elbow, knee, and hip. Inflammation of a bursa is known as bursitis.
bursa of Fabricius an epithelial outgrowth of the cloaca in chick embryos, which develops in a manner similar to that of the thymus in mammals, atrophying after 5 or 6 months and persisting as a fibrous remnant in sexually mature birds. It contains lymphoid follicles, and before involution is a site of formation of B-lymphocytes associated with humoral immunity.
bursa muco´sa (mucous bursa) (synovial bursa) a closed synovial sac interposed between surfaces that glide upon each other; it may be subcutaneous, submuscular, subfascial, or subtendinous in location.
subacromial bursa one between the acromion and the insertion of the supraspinatus muscle, extending between the deltoid and the greater tubercle of the humerus. See illustration.
Subacromial bursa, lying between the acromion and supraspinatus tendon and extending between the deltoid and greater tubercle. From Dorland's, 2000.


[bur′sə] pl. bursae
Etymology: Gk, byrsa, wineskin
1 a fibrous sac between certain tendons and the bones beneath them. Lined with a synovial membrane that secretes synovial fluid, the bursa acts as a small cushion that allows the tendon to move over the bone as it contracts and relaxes. See also adventitious bursa,bursa of Achilles,olecranon bursa,prepatellar bursa.
2 a sac or closed cavity. See also omental bursa,pharyngeal bursa. bursal, adj.


Plural of bursa.


A closed sac lined with a synovial membrane and filled with fluid, usually found in areas subject to friction, such as where a tendon passes over a bone.
Mentioned in: Joint Fluid Analysis

bursae (burˑ·sā),

n.pl membrane-lined sacs containing synovial fluid, usually found in and around joints. Bursae provide protective cushioning and lubrication.
References in periodicals archive ?
Reaction of superficial bursae in response to specific disease stimuli.
argutula differ in having a short oval signum (rather than elongate), a less spinulose ostium bursae, and no longitudinal ridge posterior of the ostium.
aa apofisi anteriores, aed phallus , an anellus, bc bursa copulatrix, cb corpus bursae, cos costa de las valvas, cor cornuti, gn gnathos, la lamella antevaginalis, lp lamella postvaginalis, sa saccus, un uncus, va valva, vi vinculum.
1h): Papillae anal small, somewhat rounded, covered with hair, apophysis posterior large, thorn-like, apophysis anterior reduced, ductus bursae large, highly covered, corpus bursa large, balloon-like with pair of rod-like sclerotised cornuti.
Materials from respective bursae were prepared and AGPT was done as previously described [3, 12].
tuberculosis, which, due to its propensity for hematogenous spread, does not show preference for particular bursae.
Formation of rice bodies has been reported in joints, (1), (2) bursae (3-6) and tendon sheaths, (5) and are commonly observed in chronic rheumatoid arthritis, seronegative inflammatory arthritis and tuberculous joints.
From this work, the University of Southampton researchers discovered that some of the swellings and associated feeling of 'walking on marbles' were related to inflamed bursae (a fluid-filled sac usually found in areas subject to friction) that had developed underneath the forefoot joints.
PVNS is a rare proliferative lesion of the synovium of joints, tendon sheaths and bursae.
In January 2009, in the nature reserve in Qinling Mountains, China, hygromas were found on the knees, stifles, hocks, haunches, and bursae between the nuchal ligament and the primary thoracic spines of 10 free-ranging takins (Budorcas taxicolor).
Chronic gout is often associated with the development of tophaceous deposits within cartilage, synovial membranes, bursae, and tendons.
This category includes conditions, such as bursitis, trigger finger, synovitis, epicondylitis, and tendonitis, that are associated with repetitive activity and that affect muscles, bursae, tendons, and fibrous tissues.