FLEXOS MUSCLES OF THE NECK. 



195 



This muscle is placed deeply : in its lower part it is crossed by the posterior belly 

 of the omo-hyoid muscle, and in its whole length it is traversed by the phrenic nerve 

 passing obliquely from above downwards and inwards. The subclavian vein and 

 artery pass respectively in front and behind its inferior attachment. The nerves 

 of the brachial plexus emerge from behind its outer border above the subclavian 

 artery. The rectus capitis anticus major arises on its inner side, the ascending 

 cervical branch of the inferior thyroid artery lies in the groove between that muscle 

 and the scalenus, and in front is the internal jugular vein. 



The scalenus medius is attached superiorly to the posterior tubercles of 

 the transverse processes of the last six cervical vertebrae ; and inferiorly 

 to a rough elevation on the first rib, extending for an inch and a half 

 forwards from the tubercle. 



In front of this muscle, between it and the anterior scalenus, are the cervical 

 nerves and the subclavian artery ; behind it are the posterior scalenus and levator 

 anguli scapulae muscles. It is sometimes attached to the transverse process of the 

 atlas. 



The scalenus posticus, smaller than the other scaleni muscles, is attached 

 above by two or three small tendons to the transverse processes of 

 as many of the lowest cervical vertebrae, and inferiorly by an aponeu- 

 rotic tendon to the second rib, in front of the attachment of the 

 levator costae. 



Fig. 168. VIEW OP THE DEEP 

 MUSCLES COKNECTED WITH 



THE UPPER PART OP THE 



VERTEBRAL COLUMN IN 

 FRONT. 





 l * ' 



The skull has been removed 

 in front of the basilar and 

 mastoid processes, together 

 with the sternum and anterior 

 parts of the first and second 

 ribs, a, cut surface of the 

 basilar process ; 6, transverse 

 process of the atlas ; e, trans- 

 verse process of the seventh 

 cervical vertebra ; d, body of 

 the first, d', of the fourth dor- 

 sal vertebra ; e, first, and e', 

 second rib ; 1, rectus capitis 

 anticus major muscle ; 2, rec- 

 tus capitis anticus minor ; 3, 

 middle part, 3', upper part, and 

 3", lower part of the longus colli ; 

 4, rectus lateralis; 4', first 

 pair, and 4", second pair of 

 intertransversales ; 5, scalenus 

 anticus of the right side ; 5', 

 the tendon of attachment to 

 the first rib on the left side, 

 the rest of the muscle having 

 been removed ; 6, scalenus 

 medius of the right side ; 6', 

 lower portion of the correspond - 

 ing muscle of the left side ; 7, 

 scalenus posticus, its superior 



attachments shown upon the left side ; 8, upper part of the levator scapulae drawn out 

 from its vertebral attachments ; 9, spleuius colli, shown in the same manner. 



o 2 



