MUSCLES OF THE TRUNK. 249 



the posterior portion. 2. To the articular tubercles of the cervical vertebrae, 

 by the inferior extremity of its fleshy fasciculi. 



Movable insertion.— The movable insertion of the great complexus is effected 

 through its superior tendon, which is fixed to the posterior face of the occipital 

 protuberance, beside the cervical tuberosity. 



Relations. — It is covered by the splenius and the trachelo-mastoideus. It 

 covers the cervical ligament, the upper branch of the longissimus dorsi, the semi- 

 spinalis colli, and the oblique and posterior straight muscles of the head. The 

 aponeurotic digitations which attach it to the dorsal transverse processes, are 

 comprised between the two branches of the longissimus dorsi. The interstice 

 which separates, inferiorly, the two portions of the muscle affords a passage to 

 the superior cervical artery. 



Action. — It is a powerful extensor of the head. 



5. Teachelo-Mastoideus (Complexus Minor) (Figs. 162, 6, 7 ; 163, 8, 9). 



iSf/nonj/TKS.— Dorso-mastoideus— GiVard. {Trachelo-mastoideus— Percivall.) 



Situation — Direction. — Situated at the internal face of the splenius, in an 

 oblique direction upwards and forwards, this muscle lies along the anterior border 

 of the complexus, and follows the inferior branch of the longissimus dorsi, wliich 

 it appears to continue to the head. 



Form — Structure. — This is a long muscle, divided into two fleshy, fusiform, 

 and parallel portions — anterior and posterior — wliich we might strictly consider 

 as two distinct muscles. Both are composed of successive fasciculi, which become 

 longer as they are superficial, and terminate by a tendon at their superior 

 extremity. The tendon of the posterior muscle is flattened, and joins the 

 mastoid aponeui'osis of the splenius. That of the anterior muscle is funicular, 

 and receives, before its insertion, a digitation from the splenius (Fig. 163, 10), 

 and another from the mastoido-humeralis (Fig. 163, 11). 



Fixed attachments. — The two fleshy portions have their fixed insertion in 

 common with the anterior portion of the great complexus : 1. On the transverse 

 processes of the two first dorsal vertebras, through the medium of aponeurotic 

 digitations which serve as an origin to the last-named muscle. 2. On the 

 articular tubercles of the cervical vertebrae, by the inferior extremity of their 

 component fasciculi. 



Movable attachments. — The terminal tendon of the posterior muscle passes to 

 the mastoid process of the temporal bone. The anterior passes to the transverse 

 process of the atlas. 



Relations. — Outwardly, with the splenius ; inwardly, with the complexus and 

 the oblique muscles of the head. The tendon of the posterior fleshy portion is 

 covered by the mastoid aponeurosis of the mastoido-humeralis. 



Action. — The trachelo-mastoideus inclines to its side the head and upper part 

 of the neck. It also acts as an extensor of the head.^ 



' Bourgelat has described, by the name of long transversal, the anterior portion of this 

 muscle, and attached it to the posterior portion of the splenius. We do not know where to find 

 one or other of these in the crude description of Lafosse and Vitet. Girard considered them, 

 like ourselves, as a single muscle, which he designates the dorso-mastoideus. Rigot has united 

 them with the anterior portion of the great complexus and the foremost fasciculi of the short 

 transverse muscle (inferior branch of the longissimus dorsi), to make his long transversal; in 

 doing so he has only complicated their description. These two muscular fasciculi being, to 

 our view, exactly represented, the posterior, at least, by the complexus minor of authropotomists, 



