DEEP LATEEAL CERVICAL MUSCLES. 



2f)J 



hyoid bone, but the lai-jTix is raised by the action of the thyi'o-hyoid muscles. 

 During deglutition the action of the thyi-o-hyoid muscles, by approximating the 

 thyi-oid cartilage and hyoid bone, facilitates the descent of the epiglottis on the 

 superior apertiure of the laiynx. 



DEEP LATEKAL AND PREVEBTEBRAL MUSCLES OF THE NECK. 



The SCALENI muscles form a group of strong muscular columns, 

 which are usually three in number, but sometimes only two. All of 

 them are subdivided superiorly into musculo-tendinous slips, corre- 

 sponding in number Avith their vertebral attachments. 



The anterior scalenus muscle is attached superiorly to the anterior 

 tubercles of the transverse processes of the third, fourth, fifth, and sixth 

 cervical vertebrae, and inferiorly by a thick flattened tendon to the 

 scalene tubercle, a rough part of the inner border and upper surface of 

 the first rib in front of the subclavian groove. 



Belations. — This muscle is placed deeply : in its lower part it is crossed by 

 the posterior belly of the omo-hyoid muscle, and in its whole length it is tra- 

 versed by the phrenic nerve passing obliquely from above doisTiwards and 

 inwards. Tlie subclavian vein and artery pass respectively in front and behind 

 its inferior attachment. The nerves of the brachial plexus emerge from behind 

 its outer border above the subclavian arteiy. The rectus capitis anticus major 

 arises on its inner side, the ascending cervical branch of the inferior thyroid 

 artery lies in the groove between that muscle and the scalenus, and in front is 

 the internal jugular vein. 



Fig. 215. — The Deep Lateral 

 AND Prevertebral Mus- 

 cles OF THE Neck from 

 BEFORE. (A. T.) \ 



a, cut surface of the 

 basilar process ; b, transverse 

 process of the atlas ; r, trans- 

 verse process of the seventb 

 cervical vertebra ; d, body of 

 the first, d', of the fourth dor- 

 sal vertebra ; e, first, and e', 

 second rib ; 1, rectus capitis 

 anticus major muscle ; 2, rec- 

 tus capitis anticus minor ; 3, 

 middle part, 3', upper part, and 

 3", lower part of the lougus colli ; 

 4, rectus lateralis ; 4', first 

 pair, and 4", second pair of 

 intertransversales ; 5, scalemis 

 anticus of the right side ; 5', 

 the tendon of attachment to 

 the first rib on the left side ; 6, 

 scalenus medius ; 6', lower por- 

 tion of the corresponding mus- 

 cle of the left side ; 7, scalenus 

 jiosticus, its superior attach- 

 ments shown upon the left side ; 

 8, upper part of the levator 

 scapulae drawn out from its 

 vertebral attachments ; 9, 

 splenius colli, sho\\'n in the 

 same manner. 



The scalenus medius is attached superiorly to the posterior tubercles 



