MUSCLES OP THE BACK. 195 



The LONG us COLLI is a long and flat muscle, consisting of two por- 

 tions. The upper arises from the anterior tubercle of the atlas, and is 

 inserted into the transverse processes of the third, fourth, and fifth cer- 

 vical vertebrae. The lower portion arises from the bodies of the second 

 and third, and transverse processes of the fourth and fifth, and passes 

 down the neck, to be inserted into the bodies of the three lower cervi- 

 cal and three upper dorsal vertebrae. We should thus arrange these 

 attachments in a tabular form : 



Origin. Insertion. 



Upper ) A , i 3d, 4th, and 5th transverse pro- 



A1 



portion. cesses. 



~) 2d and third bodies C 3 lower cervical vertebrae, bo- 

 > 4th and 5th transverse <j dies. 

 m 'J processes . . (. 3 upper dorsal, bodies. 



In general terms, the muscle is attached to the bodies and trans- 

 verse processes of the five superior cervical vertebrae above, and to the 

 bodies of the last three cervical and first three dorsal below. 



Relations. By its anterior surface with the pharynx, oesophagus, the 

 sheath of the common carotid, internal jugular vein and pneumogastric 

 nerve, the sympathetic nerve, inferior laryngeal nerve, and inferior 

 thyroid artery. By its posterior surface it rests upon the cervical and 

 upper dorsal vertebrae. 



Actions. The rectus anticus major and minor preserve the equi- 

 librium of the head upon the atlas ; and, acting conjointly with the 

 longus colli, flex and rotate the head and the cervical portion of the 

 vertebral column. The scaleni muscles, taking their fixed point from 

 below, are flexors of the vertebral column ; and, from above, elevators 

 of the ribs, and therefore inspiratory muscles. 



Eighth Group. Muscles of the Larynx. 



These muscles are described with the anatomy of the larynx, in 

 Chapter X. 



MUSCLES OF THE TRUNK. 



The muscles of the trunk may be subdivided into four natural 

 groups ; viz. 



1. Muscles of the back. 



2. Muscles of the thorax. 



3. Muscles of the abdomen. 



4. Muscles of the perineum. 



1 . Muscles of the lack. The region of the back, in consequence of 

 its extent, is common to the neck, the upper extremities, and the 



