126 



SURGICAL APPLIED ANATOMY. [Chap. ix. 



Both these layers lie in front of the depressors of the 

 hyoid bone, and they form between them a little 

 space (which extends so far laterally as to enclose the 

 sternal head of the sterno-mastoid), the widest part of 

 which is below, and which there corresponds in width 



Fig. 15. Transverse Section through the lower part of the Neck, to 

 show the arrangements of the Cervical Fascia (Diagrammatic). 



a, Trapezius ; 6, sterno-mastoid ; c, depressors of hyoid bone ; d, platysma ; 

 e, anterior spinal muscles ; /, scalenus anticus ; g, carotid artery ; h, external 

 jugular vein ; i, posterior spinal muscles ; T, trachea, with gullet behind and 

 thyroid body in front. 



to the thickness of the sternum. It will be perceived 

 that, in dividing the sternal head of the sterno- 

 mastoid , the operation is performed within this little 

 chamber formed by the two layers just named, and it 

 is well to note that the anterior jugular vein also 

 occupies this chamber on its way to the external 

 jugular trunk. This superficial layer of the fascia, 

 considered generally, would oppose in all parts the 



