242 



MUSCLES OF THE THORAX. 



descend, and each is inserted into the outer surface of the rib belonging 

 to the vertebra below that from which it springs. The levator muscles 

 belonging to the lower ribs present some longer additional fibres which, 

 passing over one rib, are inserted into the next one below ; these fibres are 

 sometimes distinguished as levatores loj^giores costarum. 



The levatores costarum lie in. series superiorly with the scaleni medius and pos- 

 ticus, and inferiorly with the external range of lumbar intertransverse muscles. 



Fig. 194. 



Fig. 194. VIEW OF THE DEEP MUSCLES OP THE ANTERIOR WALL OP THE THORAX, SEEN 

 FROM BEHIND (modified from Luschka). j 



a, back of the manubrium of the sternum ; &, clavicles ; I to XI, the anterior parts 

 of eleven ribs and costal cartilages ; 1, 1', sterno- thyroid muscle, that of the right side 

 being cut short to show more fully the next mnscle ; 2, 2', the sterno-hyoid ; 3, trian- 

 gularis sterni ; 4, upper part of transversalis abdominis united in 4', 4', the back of the 

 linea alba ; 5, attachments of the diaphragm to the lower ribs (the twelfth not represented 

 in the figure), indigitating with those of the transversalis ; 5', the two slips to the ensi- 

 form process ; 6, internal layer of intercostal muscles extending to the sternum, shown 

 in all the spaces on the right side, but only in the two uppermost of the left side ; 7, in 

 the lower spaces of the left side, indicates the external layer of intercostal muscles 

 exposed by removing the internal layer. 



