310 



PHYSIOLOGY AND HEALTH. 



resting-place for the head in its natural position, is vertically 

 over the base at the pelvis. 



716. The spine, as well as the other bones, is held in its 

 erect position by a double series of muscles, (Fig. LVH.,) 



FIG. LVII. Internal Muscles of the Back. 



a, b, Spinous processes of the 

 back-bone. 



c, Longissinus dorsi, longest 

 muscle of the back. 



d t Muscle extending from the 

 pelvis tolhe ribs. 



e, Muscles extending from the 

 vertebrae of the loins to those of 

 the back. 



/, g t Muscles extending from 

 the vertebrae of the back to those 

 of the neck. 



h, Muscle extending from the 

 back and neck to the head. 



which are placed on both sides of the back-bone, where they 

 form a cushion of flesh, and are easily felt. The lowermost 

 of these are fixed by one end to the hips, and by the other to 

 some of the bones of the back ; others are attached to one arid 

 then another of these little bones ; and others still are attached 

 to the ribs and to the back-bone. All these serve to bend the 

 back to one or the other side, and forward or backward. 



