THE BBACHIAL PLEXUS. 



381 



To 7n. 



TT\. Uvtffor a no. scp 

 and rh.QTnb-aid.euLs 



FIG. 106. DIAGRAM OF THE RIGHT BRACHIAL PLEXUS, VENTRAL VIEW ; x about 2. 



nerve of the M. lutissimus dorsi or the long subscapular nerve ( 1023). N. thr. ant. 

 (ental. cd.), N. thoracicus anterior (entails s. caudalis) The anterior thoracic nerve, 

 ental or caudal division. N. thr. post., N. thoracicus posterior The posterior thoracic 

 nerve or the external respiratory of Bell. To M. levator ang. scp. and rhomboideus 

 The nerve to the levator anguli senpulce and rhomboideus muscles. To M. clavo-deltoi- 

 deus The nerve to the davo-deltoideus muscle. 



Dissection of the Brachial Plexus. The cat should be dorsi- 

 cumbent and the arras secured laterad with cords as in Fig. 76. 

 A block should be placed flatwise under the shoulders, so that the 

 head may be slightly dorsiducted ; later in the dissection, the arm 

 may be supported by a block. The arteries should be injected 

 with thin plaster ( 345, 352, 363), from either the abdominal aorta 

 or the femoral artery. If the cat is to be used only for this prepa- 

 ration, it should be transected ( 234). 



1017. Exposure. Make a longitudinal incision through the 

 skin 2 cm. dextrad of the ventrimeson, commencing at about the 

 middle of the neck and ending opposite the base of the xiphisternum. 



