116 DISSECTION OF THE NECK. 



Besides the ganglia above mentioned, there are other ganglia in the 

 head and neck in connection with the three trunks of the fifth nerve. 



Dissection. To display the brandies of the sympathetic nerve requires 

 greater care than is necessary in tracing the white fibred nerves, for they 

 are softer, more easily torn, and generally of smaller size. In the neck 

 the ganglia and their branches have been partly prepared, and only the 

 following additional dissection will be required to bring them into view : 

 The jugular vein having been cut through, the upper ganglion will be 

 seen by raising the carotid artery, and the trunks of the vagus and hypo- 

 glossal nerves, and by cutting through the branches that unite these two 

 to the loop of the first and second spinal nerves. The several branches of 

 the ganglion are to be traced upwards on the carotid artery, inwards to 

 the pharynx, down along the neck, and outwards to other nerves. 



The dissector has already seen the middle ganglion on or near the infe- 

 rior thyroid artery, and its branches to spinal nerves, and along the neck, 

 are now to be traced. 



To obtain a view of the inferior ganglion the greater part of the first 

 rib is to be taken away, and the subclavian artery is to be cut through, 

 inside the scalenus, and drawn aside, without however destroying the fine 

 nerves that pass over it. The clavicle is supposed not to be in position. 

 The ganglion is placed on the neck of the first rib ; its branches are large, 

 and are easily followed outwards to the vertebral artery and the spinal 

 nerves, and downwards to the thorax. 



The SUPERIOR CERVICAL GANGLION is the largest of the thrfe, and is 

 of a reddish-gray color. Of a fusiform shape, it is as long as the second 

 and third cervical vertebra?, and is placed on the rectus capitis anticus 

 major muscle, beneath the internal carotid artery and the contiguous cra- 

 nial nerves. Branches connect the ganglion with other nerves ; and some 

 are distributed to the bloodvessels, the pharynx, and the heart. 



* Connecting branches unite the sympathetic with both the spinal and 

 the cranial nerves. 



* With the spinal nerves. The four highest spinal nerves have branches 

 of communication with the upper ganglion of the sympathetic ; but the 

 offset to the fourth nerve may come from the cord connecting the upper 

 to the next ganglion. 



* With the cranial nerves. Near the skull the trunks of the vagus (its 

 lower ganglion) and hypoglossal nerves are joined by branches of the 

 sympathetic. In the foramen jugulare also, both the petrosal ganglion 

 of the glosso-pharyngeal and the ganglion of the root of the vagus receive 

 small filaments, one to each, from an ascending offset of the ganglion. 



Communications are formed with several other cranial nerves by means 

 of an offset from the ganglion into the carotid canal (p. 33). 



Branches for Distribution. This set of branches is more numerous 

 than the preceding, and the nerves are larger in size. 



Branches for bloodvessels (nervi molles). These nerves surround the 

 external carotid artery, and ramify on its branches so as to form plexuses 

 on the 'arteries with the same names as the vessels : some small ganglia 

 are occasionally found on these ramifying nerves. By means of the plexus 

 on the facial artery the submaxillary ganglion communicates with the sym- 

 pathetic ; and through the plexus on the internal maxillary artery the otic- 

 ganglion obtains a similar communication. 



Another offset from the upper part of the ganglion accompanies the 

 internal carotid artery and its branches. Near the skull it divides into 



