TSE BRACHIAL PLEXUS. 



381 



771. levtchr ana- sea 

 and. th-om(raideiis 



/ectal 

 \cph. ) 



Fig. 106. — Diagbam of the Eight Brachial Plexus, Ventral View ; x about 3. 



nerve of the M. liiUssimus dorsi or tbe long subscapular nerve (§ 1033). N. thr. ant. 

 (ental. cd.), N. thoracicus anterior (entalis 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 anguU scapulcB and rhomboideus muscles. To M. clavo-deltoi- 

 deus — The nerve to the clavo-deltoideus muscle. 



Dissection of the Erachial Plexus. — The cat should be dorsi- 

 cumbent and the arms 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. 



