NERVES OF THE NECK 349 



terior end of the neck, a short distance in front of the 

 subclavian artery on either side, there is a similar 

 swelling, the inferior cervical ganglion. 



The synvpathetic nerves are of a pale pinkish colour, and 

 are not nearly so easy to see as the white cords of the pnevmo- 

 gastric and its branches. 



5. The great auricular nerve is a large branch of the third 

 spinal nerve, given off immediately after the nerve 

 emerges from the spinal canal, between the second 

 and third cervical vertebrse. It runs vertically up- 

 wards to the base of the ear, lying along the posterior 

 border of the parotid gland, and about half an inch 

 behind the angle of the jaw : it then continues its 

 course along the outer surface of the pinna of the 

 ear, as far as its tip, lying just beneath the skin. 



The nerve can readily be felt as a cord running along the 

 pinna, or seen by holding the ear up to the Ught, and looking 

 through it. 



naming determined its position in one of these ways, cut 

 down upon it, and follow it to the tip of the ear, and down- 

 wards to its point of emergence from the vertebral canal. 



6. The phrenic nerve is a branch of the fourth cervical 

 nerve, which arises just beyond the point of emer- 

 gence of this nerve from the neural canal, and runs 

 back alongside the vertebral column. Entering the 

 thorax it continues its course backwards, lying 

 between the heart and the lungs on either side, and 

 ends in the diaphragm, which it suppHes with motor 

 fibres. 



In the neck it crosses the roots of the hinder 

 cervical nerves almost at right angles. It receives 

 a small branch from the fifth cervical nerve, and 

 sometimes one from the sixth, as it passes them. 



Press the heart and right lung gently apart to expose the 

 phrenic nerve. Follow the nerve back to the diaphragm, and 

 forwa/rds along the neck to its origin. 



