i 3 6 



HEAD AND NECK 



postero-laterally with the medial surface of the carotid sheath. 

 The prevertebral layer covers the anterior surfaces of the 

 prevertebral muscles, and, passing laterally, blends with the 

 posterior aspect of the carotid sheath; then, turning round 

 the tips of the transverse processes of the vertebrae, it passes 

 backwards, covering the muscles which form the floor of the 

 posterior triangle ; and it becomes continuous with the sheaths 

 of the deep muscles of the back of the neck. 



Laterally and posteriorly, the superficial layer of the deep 

 fascia passes upwards over the sterno-mastoid and the 



trapezius to be at- 

 tached to the superior 

 nuchal lines and the 

 mastoid portions of 

 the temporal bones. 

 In the anterior cervi- 

 cal region it is at- 

 tached to the body 

 and the greater 

 cornua of the hyoid 

 bone, and then, as it 

 is prolonged further 

 upwards, it splits an- 

 teriorly to enclose 

 the submaxillary 

 gland, and posteriorly 

 to enclose the paro- 

 tid. It has been 

 noted already that 

 the lamella which 

 passes superficial to 

 the submaxillary gland is attached to the lower border , of 

 the mandible, and that which passes deep to the gland is 

 connected above to the mylo-hyoid line on the inner surface 

 of the mandible. The layer which passes superficial to the 

 parotid gains attachment to the zygoma and is prolonged 

 forwards to blend with the fascia covering the masseter. 

 The lamella which passes deep to the parotid covers its 

 postero-medial and antero-medial surfaces ; the posterior part 

 is attached above to the lower border of the tympanic plate, 

 and the anterior part to the posterior border of the petro- 

 tympanic fissure (O.T. Glaserian). It also gains an inter- 



First layer of deep fascia 

 Pretracheal layer 



Isthmus of thyreoid gland 

 Prevertebral fascia 

 First layer " 

 Second layer 

 Pretracheal la 

 Left innominate vein 



Mediastinal tissue 



FIG. 46. Diagra 



"vical Fascia 



in sagittal section. 



