THE UPPER LIMB 



291 



Action. — The muscles of the outer column act as extensors and 

 lateral flexors of the vertebral column, and as depressors of the 

 ribs, as in expiration. 



Middle Column. — This column, like the outer, is composed of 

 three muscles, which, from below upwards, are named longissimus 



Coraplexus 



Cervicaljs Ascendens 



— - Scrratus Posticus Superior 



Musculus Accessorius —^-JL. 



Loogissimus Dofsi -, 



Fig. 169. — The Deep Muscles of the Back. 



dorsi, longissimus cervicis (transversahs cervicis), and trachelo- 

 mastoid (longissimus capitis). 



Longissimus Dorsi. — ^This is the direct continuation of the inner 

 part of the erector spinae, and it is inserted in a twofold manner. 

 The inner insertions take the form of round, tapering tendons, which 

 are attached to the accessory processes of the lumbar vertebrae and 

 the extremities of the transverse processes of the thoracic vertebrae. 



