DEEP CERVICAL REGION. 53 



it has a fusiform dilatation, it maintains the same size 

 throughout, and gives off no branches ; it enters the carotid 

 canal of the temporal bone to emerge in the cranial cavity 

 for the supply of the orbit and the encephalon. This 

 vessel is sometimes tortuous instead of straight. 



The ascending pharyngeal artery, seen in this dissection, 

 is a branch of the external carotid, given off just as the 

 common carotid bifurcates. It ascends, between the inter- 

 nal carotid and the pharynx, upon the spinal column ; it 

 gives a branch to the pharynx, and near the skull, where 

 it becomes tortuous, it sends a branch through the foramen 

 lacerum posterius to supply the posterior fossa of the 

 skull (p. 45). 



The HYPOGLOSSAL NERVE lies deep beneath the internal 

 carotid ; it issues from the skull at the anterior condyloid 

 foramen, passes between the vein and artery, and descend- 

 ing curves round the occipital artery, and becomes super- 

 ficial at the lower border of the posterior belly of the 

 digastricus muscle, from whence, passing between the 

 mylo-hyoid and hyo-glossus muscles, it is directed forward 

 to the tongue and its muscles. 



The SYMPATHETIC NERVE in the neck consists of a gan- 

 gliated cord, which lies close to the spinal column ; it is 

 continuous with a similar gangliated cord in the thorax, 

 and with several ganglionic bodies in the head connected 

 with the three trunks of the fifth nerve. The cervical 

 portion of the sympathetic has three ganglia ; the superior 

 one is fusiform in shape, and an inch or more in length ; it 

 is placed on the reetus capitis anticus major muscle, beneath 

 the internal carotid artery and the trunks of the eighth 

 nerve, which must be raised to expose it. It is connected 

 with the other nerves, spinal as well as cranial, by minute 

 filaments ; some of these, called nervi molles, ramify upon 

 the branches of the carotid artery, and form plexuses on 

 their subdivisions. It sends a branch downward, behind 

 the sheath of the carotid, to the heart, called the superior 

 cardiac nerve. 



The middle cervical ganglion is situated opposite the fifth 

 cervical vertebra, lying upon or near the inferior thyroid 

 artery, whence it is sometimes called the thyroid ganglion ; 

 it is of a rounded shape, and gives off branches which con- 

 nect with the spinal nerves, and ramify upon the thyroid 

 artery ; it also gives off the middle cardiac nerve, which 

 descends to the thorax, crossing the subclavian artery, 



5* 



