VEINS OP THE NECK. 335 



at the lower border of the parotid gland, in front of the sterno-mas- 

 toid muscle. It descends the neck in the direction of a line drawn 

 from the angle of the lower jaw to the middle of the clavicle, crosses 

 the sterno-mastoid, and terminates near the posterior and inferior 

 attachment of that muscle in the subclavian vein. In its course 

 downwards it lies upon the anterior lamella of the deep cervical 

 fascia, which separates it from the sterno-mastoid muscle, and is 

 covered in by the platysma myoides and superficial fascia. At the 

 root of the neck it pierces the deep cervical fascia ; it is accompa- 

 nied, for the upper half of its course, by the auricularis magnus 

 nerve. The branches which it receives are the occipital and pos- 

 terior cervical cutaneous, and, near its termination, the supra and 

 posterior scapular. 



The external jugular vein is very variable in size, and is occa- 

 sionally replaced by two veins. In the parotid gland it receives a 

 large communicating branch from the internal jugular vein. 



The Anterior jugular vein is a trunk of variable size, which col- 

 lects the blood from the integument and superficial structures on the 

 fore part of the neck. It passes downwards along the anterior bor- 

 der of the sterno-mastoid muscle, and opens into the subclavian vein, 

 near to the termination of the external jugular. The two veins 

 communicate with each other, with the external and with the inter- 

 nal jugular vein. 



The Internal jugular vein, formed by the convergence of the 

 lateral and inferior petrosal sinus, commences at the foramen lacerum 

 posterius on each side of the base of the skull, and descends the side 

 of the neck, lying, in the first instance, to the outer side of the in- 

 ternal carotid, and then upon the outer side of the common carotid 

 artery to the root of the neck, where it unites with the subclavian, 

 and constitutes the vena innominata. At its commencement, the 

 internal jugular vein is posterior and external to the internal carotid 

 artery, and to the eighth and ninth pairs of nerves ; lower down, the 

 vein and artery are on the same plane, the glosso-pharyngeal and 

 hypoglossal nerves passing forwards between them, the pneumo- 

 gastric being between and behind in the same sheath, and the nervus 

 accessorius crossing obliquely behind the vein.. 



The Branches which the internal jugular receives in its course 

 are, the facial, the lingual,'ihe inferior pharyngeal, the occipital, and 

 the superior and inferior thyroid veins. 



The Vertebral vein descends by the side of the vertebral artery 

 in the canal formed by the foramina in the transverse processes of 

 the cervical vertebrae, and terminates at the root of the neck in the 

 commencement of the vena innominata. In the lower part of the 

 vertebral canal it frequently divides into two branches, one of which 

 advances forwards, while the other passes through the foramen in 

 the transverse process of the seventh cervical vertebra, before 

 opening into the vena innominata. 



The Branches which it receives in its course are the posterior 



