MUSCLES OF THE TRUNK. 



247 



unites it to the mastoid tendon of the trachelo-mastoideus, and passes to the 

 mastoid crest. The second joins a very strong tendon common to the splenius, 

 the trachelo-mastoideus, and the mastoido-humeralis, which tendon is attached to 

 the transverse process of the atlas (Fig. 162, 9). The two or three others 

 are directly inserted into the transverse processes of the third, fourth, and fifth 

 cervical vertebras. 



Relations.— ThQ splenius is related, outwardly, to the rhomboideus, the 



Fig. 159. 



StrPERFICIAL MUSCLES OF THE NECK AND SPINAL REGION OF THE BACK AND LCI 



1, Dorsal trapezius; 2, longissimus dorsi ; 3, cervical trapezius ; 4, angularis scapulae; 5, spleniu 

 6, anterior, or superficial portion of the mastoido-humeralis; 7, its humeral iusertion ; 7', its 

 mastoid insertion; 8, the thin aponeurosis uniting this insertion to the sterno-maxillaris ; 8' 

 posterior portion of the mastoido-humeralis ; 9, its inferior aponeurosis inserted into the inter 

 stice of the long abductor of the arm; 10, sterno-maxillaris; 11, subscapulo-hyoideus ; 12 

 portion of the cervical panniculus; 13, portion of the great extensor of the forearm ; 14, posterior 

 belly of the long abductor of the arm ; 15, great pectoral muscle. 



angularis scapulae, cervical trapezius, and mastoido-humeralis ; inwardly, to 

 the complexus and the two oblique muscles of the head ; by its inferior border, 

 to the superior margin of the inferior branch of the longissimus dorsi. 



Action.— It extends the head and neck in inclining them to one side. If the 

 two act in concert, the extension is direct. 



