HIPPOPATHOLOGY. 



VOL. IV.—PART II. 



DISEASES OF THE BURSiE MUCOSAE AND SYNOVIAL 



SHEATHS. 



NO person having any pretension to anatomical knowledge need 

 be told that the parts named, or rather misnamed, by the old ana- 

 tomists BURS^ MUCOSA, are not bags of mucus, but bags con- 

 taining a fluid similar in its aspect and properties to synovia or 

 joint oil ; and that the sheaths of tendons, " the synovial sheaths" 

 as they are usually called, are kindred structures to them. The 

 bursa mucosa consists simply of a membrane, of the same texture 

 as synovial membrane, thrown into the form of a sac or bag. The 

 synovial sheath nothing differs from it save that the membranous 

 sac is commonly prolonged and enlarged, and is apt to run into 

 divers complex and irregular shapes. Both bursa and sheath form 

 circumscribed inclosures ; and in this respect both bear considera- 

 ble analogy, as well as in the texture of their membranous walls, 

 to the shut cavities of the joints. Dr. Alexander Munro* satis- 

 factorily established the identity in structure, sensibility, and dis- 

 ease, between the bursas and the capsular ligaments of joints. He 

 found the membrane composing one and the other thin and dense, 

 and possessing little sensibility in health, but great sensibility in 

 a state of inflammation ; and, though transparent in the bursa, as 

 capable as the capsular hgament of confining air or any other 

 fluid. That the cavity of the bursa should be shut, the same 



* In that section of his works entituled, " A Description of all the Bursa; 

 Mucosae of the Human Body." Edinburgh^ 1785. 

 VOL. IV. N n 



