486 



MUSCLES OF ANTERIOR NECK. 



of the omo-hyoid, above the clavicle, and behind the poste- 

 rior inferior margin of the sterno-mastoid. The sub-davian 

 artery and some of its branches, with the vein and brachial 

 plexus of nerves, are seen in this triangle. 



The scalenus anticus muscle is situated at the lower and 

 anterior part of the neck, and is considered to be contin- 

 uous with the rectus capitis F JG . 143. 

 anticus major. It arises ten- 

 dinous from the third, fourth, 

 fifth, and sixth transverse pro- 

 cesses of the cervical vertebrae, 

 and is inserted into the su- 

 perior surface of the first rib at 

 its sternal end. 



The scalenus medius is larger 

 than the last and arises from 

 the transverse processes of all 

 the cervical vertebrae by tendin- 

 ous fibres. Sometimes it orig- 

 inates only from the four or five 

 lower cervical vertebrae. It is 

 inserted into the superior sur- 

 face of the first rib posterior to the subclavian artery. 



The scalenus posticus is behind the former, and is better 

 seen in dissecting the muscles of the spine. It arises from 

 the transverse processes of the two or three lower cervical ver- 

 tebrae, and is inserted into the superior surface of the second 

 rib between its tubercle and angle. The two last muscles are 

 by some regarded as a single one, and described as such. 



Function. The three scaleni bend the neck forward or to 

 one side, and when the vertebrae are fixed, elevate the ribs. 

 The first scalenus has the phrenic nerve descending on the 

 front, the subclavian vein crossing its insertion, the sub- 



FIG. 148 represents the deep Muscles of the anterior Neck, a Rectus capi- 

 is anticus major, d Rectus capitis anticus minor, j Rectus capitis lateralis. 

 6 Scalenus anticus. g Scalenus medius. h Scalenus posticus. c f Longus 

 colli its lower portion on the right side, and upper portion on the left side, 

 i One of the intertransversales. 



