186 FASCIiE IN GEXEEAL. 



kinds into the looser varieties of connective tissue ; wliilo the latter, 

 denser in character, frequently exhibit more or less regular arrangements 

 of strong white fibres, giving thera a shining appearance, and are often 

 termed aponeuroses. 



Superficial Fascia. — Untler this name, or as svhriitaneons fascia, is 

 described the layer of loose tissue of varying density, which is placed 

 immediately below the skin, all over the body. Tt is the web which 

 contains the subcutaneous fat, the j^f^nnindus adiposus, and in some 

 regions su]3erficial muscles, as the pannimlas carnosns. Fi'om the sub- 

 cutaneous tissue of tlie eyelids, however, as well as from that of tlie penis 

 and scrotum, adipose matter is entirely absent. Beneath the fatty layer 

 of the superficial fascia, which is immediately subcutaneous, there is 

 generally another layer of the same structure, comparatively devoid of 

 adipose tissue, in which the trunks of the subcutaneous vessels and 

 nerves are found. AVhen the subcutaneous fat becomes absorbed, the 

 stroma in which it was deposited is still left, and its meshes approacli 

 one another, so that in lean subjects a more fibrous condition of the 

 superficial fascia is found than in others. 



Deep FasciEB and Aponeuroses. — Under the name of deep fascia is 

 comprehended that stronger layer of fibrous or connective tissue which, 

 lying close to the muscles, invests them, or dips between them, and 

 forms a nearly continuous covering of the body beneath the superficial 

 fascia. It is chiefiy to the stronger parts of this fascia that the name 

 of aponeuroses has been given. Those covering the muscles have been 

 named ajwnenroses of invesiment (Bichat), to distinguish them from 

 proper tendinous expansions, or ajwneiiroscs of 'insertion, of muscles. 

 This distinction, however, is far from being universally applicable : apo- 

 neuroses of insertion are often continued into aponeuroses of invest- 

 ment, as in the instance of the glutens maximus, or into softer ftiscia. 

 as at the lateral parts of the occipito-frontal aponeurosis. The principal 

 aponeuroses of investment are those which incase the muscles of the 

 limbs, binding them down in a common sheath, and connected in various 

 places by septa with the bones. They are characteristic of the limbs, 

 there being no structure entirely corresponding to them in the rest of 

 the body. Parts of the deep ftiscia; in the vicinity of the larger joints 

 as at the wrist and ankle, become strengthened into tight transverse 

 bands, which serve to hold the tendons close to the bones, and hence 

 receive the name of re\iiiinnda. 



Synovial Sacs and Sheaths : Bursse Mucosae. — In various situ- 

 ations where tlie tendons of muscles pass over the prominences of 

 bones, or run in fibrous sheaths, synovial cavities exist, either of a 

 vesicular or tubular form, thus forming the synovial h/irsec or shadhs. 

 In many such instances a true synovial membrane appears to cover the 

 adjacent surfaces, and diminishes their friction in moving on eaeh 

 other. In other places less defined spaces exist in the connective tissue 

 between parts of the tendons or fascia3, and occasionally between parts 

 of the skin and the harder or more prominent structures on which they 

 lie. In some of these subcutaneous burste a distinct synovial mem- 

 brane cannot be found ; but there are prol)ably gradations of transition 

 between these bursal spaces and those which are lined by synovial mem- 

 brane. Some of the synovial sacs and sheaths of tendons in the 

 vicinity of joints communicate freely Avith the articular cavities. (See 

 (Jen. Anat., vol. ii. p. -^»1.) 



