OP THE ENVELOPES OP THE MUSCLES. 335 



muscles of the limbs and binds them down to the bones. 

 These membranes have the form of sheaths; their external 

 surface corresponds to the cellular and adipose tissues, as well 

 as to the subcutaneous vessels and nerves. Their inner sur- 

 face corresponds to the muscles, furnishes attachments to some 

 of them, sends laminae between the greater number of them, 

 partitions, prolongations which separate them from each other, 

 which furnish attachments to them, and terminate by inserting 

 themselves on the ridges and lines of the bones. Their ex- 

 tremities are attached to the bones, receiving insertions or ex- 

 pansions of the tendons, losing themselves insensibly in the 

 cellular tissue, and in other places forming annular ligaments 

 to the tendons. They consist of one or more layers of liga- 

 mentous tissue of variable thickness, and are proportionate in 

 their thickness to the number and strength of the muscles that 

 they embrace; they present openings for the passage of vessels 

 from the deep to the superficial plane and vice versa. They 

 are provided with tensor muscles, either proper, or simply by 

 the expansion of their tendons. Their uses are to keep the 

 muscles in their proper places, and to furnish them with points 

 of attachment. They exercise by their resistance a slight 

 pressure on the deep vessels, and thus favour the venous and 

 lymphatic circulation. Their knowledge is of great im- 

 portance in a pathological point of view, on account of the 

 strangulations which they may induce; nor is its knowledge 

 less so in surgery, in consequence of their relations with the 

 muscles and vessels. 



The thigh, the leg, the foot, the hand, the fore-arm and arm, 

 are provided with aponeuroses of this kind. 



520. The aponeuroses of the parietes of the cavities of the 

 trunk, or the partial aponeuroses, invest, cover, and even en- 

 velop, at least in part, certain muscles: such are the compound 

 aponeurotic sheaths of the recti and pyramidales muscles of 

 the abdomen; the dorsal aponeurosis which covers the muscles 

 of the vertebral grooves; the temporal aponeurosis; the pelvic, 

 transversal, superficial, jugular aponeuroses, &c. Some, and 

 especially the latter, are not very distinct from the cellular 

 tissue, into which they are continued. 

 44 



