MUSCLES OF THE HACK. 



Spinalis Dorsi, from the last 2 dorsal and FIG. 40. 



first 2 lumbar spines, into all the remaining 

 dorsal spines. Action, to erect the spinal 

 column. Nerves, branches of the dorsal. 



Spinalis Colli,/;w/z the 5th and 6th cervical 

 spines, sometimes from the 1st and 2d 

 dorsal, into the spine of the axis, or the 

 3d and 4th cervical spines. Action, to 

 steady the neck. Nerves, branches of the 

 cervical. [This muscle is frequently ab- 

 sent.] 



Biventer Cervicis, from the transverse pro- 

 cesses of 2 to 4 upper dorsal- vertebrae, 

 into the superior curved line of the occipi- 

 tal bone. [Is but a portion of the corn- 

 plexus muscle.] 



Complexus, 8 by 7 tendons from the tips of 

 the transverse processes of the 7th cervical 

 and 3 upper dorsal vertebrae, and from the 

 articular processes of the 4th, 5th, and 6th 

 cervical, into the inner depression between 

 the curved lines of the occipital bone. Ac- 

 tion, to retract and rotate the head. Nerves, 

 suboccipital, great occipital, and branches 

 of the cervical nerves. 



Semispinalis Dorsi, 10 from the transverse 

 processes of the dorsal vertebrae, from 

 about the 5th to the I ith, into the last 2 



cervical and 4 upper dorsal spines. Action, to erect the spinal column. 

 Nerves, branches of the dorsal nerves. 



Semispinalis Colli, 11 from the transverse processes of the 4 upper dorsal 

 vertebrae, and the articular processes of the 4 lower cervical, into the 2d, 

 3d, 4th, and 5th cervical spines. Action, to erect the spinal column. Nerves t 

 branches of the cervical. 



Multifidus Spinae, 16 from the back of the sacrum, posterior superior spine of 

 the ilium, posterior sacro-iliac ligaments, articular processes of lumbar and 

 cervical vertebrae, and the transverse processes of the dorsal, into the 

 laminae and spines of the next 4 vertebrae above. Action, to erect and rotate 

 the spinal column. Nerves, posterior spinal branches. 



