THE BACK. 



43 



Erector Spinae and Branches. Remove the vertebral aponeurosis (Fig. 

 282) and expose the fifth layer of muscles and its subdivisions. (Fig. 283.) 



Complexus 



Splenius capitia 



Splenius colli 



Serratus postieus superior 



Vertebral aponeurosis 



Serratus postieus 

 inferior 



Obliquus interims 



Origin of latissimus 

 dorsi 



SEVENTH CERVICAL VERTEBRA 



TWELFTH THORACIC VERTEBRA 



FIFTH LUMBAR VERTEBRA 



FIG. 282. THE THIRD AND FOURTH LAYERS OF THE MUSCLES OF THE HACK. 



Origin. (i) The spines of the two last thoracic, all the lumbar, and the four 

 upper sacral vertebrae ; (2) the back of the side portion of the fourth sacral 



