296 MUSCLES OF THE HEAD AND NECK. 



of the transverse processes of the last six cervical vertebrt^ ; and 

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

 and a half forwards from the tubercle. 



JleJationn. — In front of this muscle, between it and tlie anterior scalenus, are 

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

 and levator anguli scapulas muscles. 



Varktie.i.—This muscle sometimes arises from the transverse processes of all 

 the cervical vertebra. It takes the jilace of the first levator costaj. 



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

 attached above by two or three small tendons to the transverse pro- 

 cesses of as many of the lowest cervical vertebras, and inferiorly by an 

 aponeurotic tendon to the second rib, between its tubercle and angle, in 

 front of the attachment of the second levator costte, 



Iti'lationx. — This muscle is partly covered by the middle scalene muscle, and is in 

 contact by its posterior surface with the levator costee and cervicalis ascendens 

 muscle. 



Varieties. — The scaleni muscles are subject to some amount of variation, both 

 in the number of their points of attachment, and in the arrangement of their 

 fibres. A slip from the scalenus anticus sometimes passes behind the subclavian 

 artery. 



The Prevertebral muscles of the cervical region consist of three, 

 of which two pass to tlie head from the upper vertebrae, viz., the recti 

 capitis antici major and minor, and the third is confined to vertebral 

 attachments, the longus colli. Along with these the rectus capitis 

 lateralis muscle may also be described in this place. 



The rectus capitis anticus major muscle arises by tendinous 

 slips from the anterior tubercles of the transverse processes of the 

 third, fourth, fifth, and sixth cervical vertebrae : it is inserted into 

 the basilar process of the occipital bone, a litlle in front of the foramen 

 magnum. The muscles of opposite sides converge as they ascend, and 

 their mesial fibres are longest. 



lldaftonft. — The anterior surface of the rectus capitis anticus major supports 

 the pharynx, the sympathetic and vagus nerves, and the great cervical vessels. 

 The posterior siurface rests upon part of the longus colli and the rectus anticus 

 minor. 



The rectus capitis anticus minor, under cover of the preceding 

 muscle, arises from the anterior arch of the atlas, and slightly from the 

 root of its transverse process ; it is inserted into tlie basilar process, 

 between the margin of the foramen magnum and the preceding muscle, 

 half an inch from its fellow. 



The rectus capitis lateralis is a sliort thick muscle arising from 

 the upper surface of the anterior division of the transverse process of the 

 atlas, and inserted into the rough surface beneath the jugular eminence 

 of the occipital bone. It completes tlie series of intertransversales 

 muscles, which are described along with the deep posterior muscles of 

 the neck. 



liclations. — Th-e anterior surface of this muscle is in contact vdth the internal 

 jugular vein, the posterior v.'ith the vertebral artery. 



The longus colli muscle rests on the front of the vertebral column 

 from the atlas to the third dorsal vertebra : it consists of three sets of 

 fibres, of which two are oblique, and one vertical, a. The superior 



