NECK. 



567 



general investment; being prolonged without 

 interruption, below, into tlie superficial fascia 

 of the chest, above, into that of the head and 

 face. It consists here, as elsewhere, of two 

 layers, which have the local peculiarity of 

 being separated by the platysma myoides in the 

 greater part of their extent. Its deeper layer 

 occurs in the form of delicate, scarce, lax, fat- 

 less areolar tissue, interposed between the 



Fig. 



proper aponeurosis of the region and the pla- 

 tysma myoides, furnishing means for the loose 

 gliding of this muscle, and continued, without 

 adhesion or sensible change, into the adjoining 

 regions. Its subcutaneous layer is of coarser 

 materials and of less uniform thickness, is in 

 close union with the skin, and follows its move- 

 ments : it contains the variable amount of fat, 

 which the region presents ; and so, though it 



327. 



Transverse horizontal section of the neck, seen from 



A, fourth cervical vertebra. , 

 H, cricoid cartilage. 



C, pharynx. 



D, Medulla spinalis. 



, prevertebral aponeurosis. 



I, posterior pharyngeal aponeurosis. 



c, middle constrictor. 



d, thyroid body. 



e, sterno-mastoid muscle, in the space behind which 

 is seen a section of the great vessels, and of their 

 sheath. 



f, stemo-hyoideus. * 

 ff, omo-hyoideus. 

 h, sterno-thyroideus. 

 ', crico-thyroideus. 



j, trapezius. 



k, splenius. 



I, complexus. 



m, semi-spinalis and multifidus. 



n, levator anguli scapula;. 



o, scalenus posticus. 



p, scalenus anticus. 



</, longus colli. 



r, rectus capitis anticus major. 



s, superior thyroid vessels. 



t, ascending cervical vessels, j 



u, deep cervical vessels. 



ii, external jugular vein. 



w, anterior jugular vein. 



x, platysma and superficial fascia. 



