GREAT VESSELS AND NERVES OF NECK 215 



vein lies postero-lateral to the upper end of the cervical 

 part of the internal carotid artery, from which it is partially 

 separated by the last four cerebral nerves. As it descends 

 it assumes a more directly lateral relationship, first to the 

 internal carotid and then to the common carotid, overlapping 

 each vessel to a slight extent anteriorly; and it is enclosed, 

 with them and the vagus nerve, in a common sheath of deep 

 cervical fascia, the nerve lying in its own compartment of the 

 sheath between the vein laterally and the arteries medially, 

 and in a posterior plane (Figs. 47, 48, 53). 



The superficial or lateral relations of the vein in the upper 

 part of its extent are the styloid process, with the stylo- 



ryn 



Thyreo-hyoid membrane 



Plica vocalis 

 Processus vocalis 

 Arytaenoid cartilage 



Platysma 

 Posterior wall 



of phar 

 Retropharyn- 

 geal space 



Carotid shea 



Scalenus anterior 



M. longus colli 



M. 



M. sternohyoideus 



. thyreohyoideus 



Thyreoid cartilage 

 M. omohyoideus 



ecessus piriformis 

 Superior thyreoid 

 Descendens 

 hypoglossi 

 ^Common carotid 

 Internal jugular 



Vagus 



Vertebral artery 



Sympathetic trunk 



FIG. 79. Transverse section through the Neck at the level of upper 

 part of Thyreoid Cartilage. 



pharyngeus and stylo-hyoid muscles, and the posterior belly 

 of the digastric, which separate it from the upper part of the 

 postero-medial surface of the parotid gland. In that part 

 of its extent it is crossed superficially, along the upper border 

 of the posterior belly of the digastric, by the posterior 

 auricular artery, and at the lower border of the digastric 

 by the accessory nerve, passing downwards and backwards, 

 and by the occipital artery, passing upwards and backwards, 

 superficial to the nerve. At a slightly lower level it is con- 

 cealed by the lower part of the postero-medial surface of the 

 parotid, and it is crossed by the sterno-mastoid branch of 

 the occipital artery. After it emerges from under cover of 

 the parotid, it lies under cover of the anterior border of the 

 m 14 c 



