204 MUSCLES OF THE BACK. 



with the spinal column in the lumbar region, and the vertebral aponeu- 

 rosis with the ribs and spinal column in the dorsal region, form a com- 

 plete osseo-aponeurotic sheath for the erector spinae. 



The CERVICALIS ASCENDENS is the continuation of the sacro-lumbalis 

 upwards into the neck. It arises from the angles of the four upper ribs, 

 and is inserted by slender tendons into the posterior tubercles of the trans- 

 verse processes of the four lower cervical vertebrae. 



Relations. By its superficial surface with the levator anguli scapulae ; 

 by its deep surface with the upper intercostal muscles and ribs, and with 

 the intertransverse mu cles ; externally with the scalenus posticus ; and 

 internally with the transversalis colli. The tendons of insertion are inter- 

 posed between the attachments of the scalenus posticus and transversalis 

 colli. 



The TRANSVERSALIS COLLI would appear to be the continuation up- 

 wards into the neck of the longissimus dorsi ; it arises from the transverse 

 processes of the five upper dorsal vertebrae, and is inserted into the pos- 

 terior tubercles of the transverse processes of the five middle cervical 

 vertebrae. 



Relations. By its superficial surface with the levator anguli scapulae, 

 splenius and longissimus dorsi. By its deep surface with the complexus, 

 trachelo-mastoideus and vertebrse ; externally with the musculus accesso- 

 rius ad sacro-lumbalem, and cervicalis ascendens ; internally with the 

 trachelo-mastoideus and complexus. The tendons of insertion of this 

 muscle are interposed between the tendons of insertion of the cervicalis 

 ascendens on the outer side, and of origin of the trachelo-mastoid on the 

 inner side. 



The TRACHELO-MASTOID is likewise a continuation upwards from the 

 longissimus dorsi. It is a very slender and delicate muscle, arising from 

 the transverse processes of the four upper dorsal and four lower cervical 

 vertebrae, and inserted into the mastoid process to the inner side of the 

 digastric fossa. 



Relations. The same as those of the preceding muscle, excepting that 

 it is interposed between the transversalis colli and the complexus. Its 

 tendons of attachment are the most posterior of those which are connected 

 with the posterior tubercles of the transverse processes of the cervical ver- 

 tebrae. 



The COMPLEXUS is a large muscle, and with the splenius forms the 

 great bulk of the back of the neck. It crosses the direction of the splenius, 

 arising from the transverse processes of the four upper dorsal, and from 

 the transverse and articular processes of the four lower cervical vertebra?, 

 and is inserted into the rough surface on the occipital bone between the 

 two curved lines, near the occipital spine. A large fasciculus of the com- 

 plexus is so distinct from the principal mass of the muscle as to have led 

 to its description as a separate muscle under the name of biventer cervicis. 

 This appellation is not inappropriate, for the muscle consists of a central 

 tendon, with two fleshy bellies. The complexus is crossed in the upper 

 part of the neck by a tendinous intersection. 



Relations. By its superficial surface with the trapezius, splenius, tra- 

 chelo-mastoid, transversalis colli, and longissimus dorsi. By its deep sur- 

 face with the semi-spinalis dorsi and colli, the recti and obliqui. It is 

 separated from its fellow of the opposite side by the ligamentum nuchse, 

 and from the semi-spinalis colli by the profunda cervicis artery and prin- 



