14 TOPOGEAPHICAL AXATOMY OF 



N. ACCESSOKius. — The dorsal branch of the accessory or eleventh 

 cerebral nerve passes down the neck partly under cover of the brachio- 

 cephalic muscle. Nearing the scapula, its course becomes more 

 horizontal and lies between the trapezius muscle, which covers the 

 nerve, and the ventral serrate, prescapular part of the deep pectoral 

 and the supraspinous muscles, which are crossed in succession. The 

 accessory nerve comes to an end in the thoracic part of the trapezius. 



M. BRACHIOCEPHALICUS. — By far the greater part of the brachio- 

 cephalic^ muscle belongs to the neck; but the dissector of the limb 

 should examine its connection with the line continuing the crest of 

 the greater tubercle of the humerus beyond the deltoid tuberosity 



M. biceps brachii. 



Coracoid process 



M. coracobrachialis. 



.Glenoid cavity. 

 M. tei'es minor.' 



Fig. 7. — Glenoid Cavity of the Scajmla, with Areas of Muscular Attachment in its 



Neiglibourhood. 



and the strong fascia on the lateral aspect of the arm. Just cranial 

 to the level of the shoulder joint the muscle is pierced by a branch of 

 the sixth cervical nerve that is distributed to the skin of this region. 



M. PECTORALis PROFUNDUS (PARS PRAESCAPULARis). — If the brachio- 

 cephalic muscle be divided on a level with the shoulder joint and the 

 cut ends turned aside, the prescapular part of the deep pectoral will 

 be seen running along the edge of the scapula, to be attached to the 

 surface of the supraspinous muscle. 



Dissection. — If the rhomboid and latissimus dorsi muscles be now 

 divided, the limb can be removed from the trunk. The dissector should 

 then direct his attention to the structures on the medial aspect of the 

 scapular region and the arm. The axillary vessels and their branches 

 are to be cleaned and the fibrous tissue adherent to those nerves that 

 supply the limb is to be removed, beginning at the most proximal part 

 of each nerve. Finally, such muscles as are visible must be defined and 

 cleaned. 



Lymph glands of the arm. — In clearing away the fibrous tissue 

 from the vessels and nerves that cross the distal part of the teres 



1 Brachium [L.], /Spaxiwv (brachion) [Gr.], the arm (above the elbow). Cephalicus 

 [L.], K€<f)aXLK6<s (cephalicos) [Gr.], pertaining to the head (KitpaX-q). 



