

THE OSSEOUS SYSTEM. 



fibrous layers — the fibrous capsules as they are termed, — as on 

 cursory inspection to present the aspect of tolerably tough 

 capsules. These fibrous coats arc met with especially in 

 situations where the articulation is either wholly unprotected, 

 or but thinly covered by soft parts, or where a very firm 

 connection is required (as in the hip-joint) ; they are absent for 

 the most part, or are undeveloped, where muscles, tendons, and 

 ligaments rest upon the articulation, or where, for special 

 purposes, the synovial membrane is exposed to more considerable 

 movements (as in the knee and elbow). 



The relation of the articular capsules to the bones and 

 articular cartilages, more precisely described, is as follows 

 (fig. 126) : — The articular capsule is attached, either simply to 

 the border of the cartilaginous surface, Fio . 126 



extending thence directlv to the other 

 bone {patella, ampJiiarthroses) ; or it may, 

 in the first place, besides the border of 

 the cartilage, also invest a larger or 

 smaller extent of surface of the bone 

 itself, and then pass to the second bone, 

 with which it is connected in the one 

 way or the other. In either of these 

 cases the svnovial membrane does not 

 adhere immediately to the hard tissues 

 subjacent to it, but is more or less closely 

 connected with the periosteum and perichondrium, ultimately 

 ceasing without any distinct margin, not far from the border of 

 the articular cartilage, with the perichondrium of which it is 

 inseparably united. 



With respect to the intimate structure of these tissues, the 

 synovial membranes, distinct from the fibrous capsules, as they 

 are termed, which possess in all respects the structure of 

 fibrous ligaments, consist : — 1 . of a layer of connective tissue, 

 with not very numerous vessels and nerves; and 2. of an 

 epithelium. The latter is composed of from one to four layers 

 of large tesselated cells, measuring 0*005 — 0*008"', with 



Fig. 126. Diagram of a transverse section of a phalangeal articulation, partly after 

 Arnold: a, bones; b, articular cartilage; c, periosteum continuous with theperichon- 

 drium of the articular cartilage; d, synovial membrane at the edge of the cartilage, 

 connected at first with the perichondrium; e, its epithelium. 



