DORSUM OF THE ARM 



Teres minor 

 Infraspinatus 



Triceps (lateral i 

 head) 



Deltoid 4i : 



Brachialis -- 

 Sulcus for radial 



ulna. The superficial 

 part of the muscle is, for 

 the most part, formed by 

 the long head and the 

 lateral head of the muscle. 

 The medial head is deeply 

 placed ; only a very small 

 portion of it appears super- 

 ficially, in the distal part 

 of the arm, on each side 

 of the common tendon of 

 insertion. 



The long head of the 

 triceps arises, by a flattened 

 tendon, from the rough 

 triangular impression on 

 the upper part of the 

 axillary border and the 

 lower aspect of the neck 

 of the scapula in the in- 

 terval between the teres 

 minor and subscapularis 

 muscles (Fig. 24, p. 46). 



The two humeral heads 

 take origin from the pos- 

 terior aspect of the hum- 

 erus ; and if it is borne in 

 mind that no fibres arise 

 from the sulcus for the 

 radial nerve and that the 

 groove intervenes between 

 the origins of the two 

 heads, their relations will 

 be easily understood. The 

 dissector should provide 

 himself with a humerus, 

 and, having first identified 

 the sulcus for the radial 



nerve, proceed to map out 



. FIG. 48. Dorsal aspect of the Humerus 



the areas Of attachment with Attachments of Muscles mapped out. 



of the humeral heads of 



the triceps as they are exhibited in the dissected part. 



VOL. I 8 



Medial epi- 

 condyle 



"| Origin 

 J-ofex- 

 J tensors 



Anconaeus 



