GREAT VESSELS AND NERVES OF NECK 317 



Dissection. In the dissection of the neck the greater part of the cervical 

 sympathetic, with the branches which proceed from it, has been displayed. 

 The inferior ganglion, which lies deeply in the hollow between the 

 transverse process of the seventh cervical vertebra and the neck of the first 

 rib, is still to a certain extent concealed, and must now be displayed. 

 Dislodge the subclavian artery from its place on the first rib behind the 

 scalenus anterior muscle, and turn it medially. To do this efficiently, 

 it will be necessary to cut the costo-cervical artery at its origin. Great care 

 must be taken to preserve uninjured the fine nerves which proceed down- 

 wards anterior to the first part of the subclavian artery. If more space for 

 the dissection is required, the anterior part of the first rib may be removed 

 by the bone-forceps, but, as a general rule, this will not be necessary. 



Truncus Sympathicus in the Neck. The cervical part of 

 the sympathetic trunk takes a vertical course through the neck, 

 anterior to the roots of the transverse processes of the vertebrae. 

 It lies between the internal and common carotid arteries 

 anteriorly and the longus capitis (O.T. rectus capitis anticus 

 major) and longus colli muscles posteriorly. Above, it is pro- 

 longed upwards in the form of a stout, ascending nerve-trunk, 

 the nervus caroticus internus, which accompanies the internal 

 carotid artery into the carotid canal ; below, it becomes con- 

 tinuous, over the neck of the first rib and posterior to the 

 apex of the pleura, with the thoracic portion of the sympa- 

 thetic. Only three ganglia are developed upon this part of 

 the trunk and no white rami communicantes from the cervical 

 nerves enter either the trunk or the ganglia. 



Ganglion Cervicale Superius. This, the largest of the 

 three ganglia, is an elongated fusiform body which varies 

 somewhat in size. It is placed upon the upper part of the 

 iongus capitis, opposite the second and third vertebrae, and 

 posterior to the carotid sheath. From its upper end the stout 

 nervus caroticus internus passes into the carotid canal, whilst 

 its lower end tapers into the downward continuation of the 

 trunk. Numerous branches issue from it ; of these some 

 connect it with neighbouring nerves, whilst others are 

 distributed in various ways. 



The connecting branches are: (i) slender grey rami 

 communicantes which connect it with the upper four cervical 

 nerves ; (2) twigs to both ganglia of the vagus ; (3) to the 

 petrous ganglion of the glosso-pharyngeal ; and (4) to the 

 hypoglossal. It is not connected with the accessory. 



The branches of distribution are: (i) nervus caroticus 

 internus; (2) nervi carotici externi ; (3) rami laryngo- 

 pharyngei ; (4) nervus cardiacus superior. 



