CERVICAL PORTION OF THK SYMPATHETIC SYSTEM. 



517 



bundle, which gains the origin of the three terminal divisions of 

 the primitive carotid ; and 3rd, Small filaments supplying the 

 guttural pouch and pharynx. 



1. The branches which accompany the carotid, generally two 

 in number, the anterior being largest, wind round the artery, and 

 communicate one with the other. Extending to the cavernous sinus, 

 they form the cavernous plexus, by which they communicate with 

 many of the cranial nerves, and send filaments to join analogous 

 filaments from the opposite side. A branch' from this plexus joins 

 the superficial petrosal nerve, and contributes to the formation 

 of the Vidian nerve, which joins the spheno -palatine ganglion. 



thorax opeiietl from the left side to show the nerves. 1, Heart ; 2, Anterior aorta ; 3, rosterior 

 aorta ; 4 4, Trachea ; 5 5, (Esophagus ; 6, Seventli ; 7, Eighth cervical nerves ; S, First dorsal 

 nerve ; 9 9, Diaphragm ; a, Point of separation of sympathetic and pneumogastric ; b, Pneumo- 

 gastric ; c c, Eecurrent ; d, Cardiac ; e, Superior ; /, Inferior branch of the pneumogastric ; <j i) g. 

 Phrenic; g' </", Its roots, from the sixth and seventh cervicals ; 7(, End of cervical portion of 

 sympathetic cord; i, Inferior cervical ganglion; h. First dorsal ganglion; I I I, Thoracic part of 

 sympathetic cord; m m, Union of sympathetic and dorsal nerves; n, Continuation of sympathetic; 

 0, Splanchnic. 



In company with fibres from the ophthalmic branch of the fifth, 

 it communicates with the ophthalmic ganglion, and also sends a 

 filament to the Gasserian ganglion, and mingles its fibres with 

 those of the third, fourth, and sixth cranial nerves, or motor nerves 

 of the eye. 



