THE SYMPATHETIC NERVES. 



1. ASCENDING BRANCH AND CRANIAL PLEXUSES. The ascending or carotid 

 branch of the first cervical ganglion (n. caroticus internus) is soft in texture and of 

 a reddish-grey tint, seeming to be in some degree a prolongation of the ganglion 

 itself. In its course to the skull, it is concealed by the internal carotid artery, 

 with which it enters the carotid canal in the temporal bone, and it is then divided 

 into two parts, which are placed one on the outer, the other on the inner side of the 

 vessel. 



The external division distributes filaments to the internal carotid artery, receives 

 one or two carotico-tympanic twigs from the tympanic branch of the glosso- 

 pharyngeal (p. 2 GO), and, after communicating by means of other filaments with the 

 internal division of the cord, forms the carotid plexus. 



The internal division, rather the smaller of the two, supplies filaments to 

 the carotid artery, and goes to form the cavernous plexus. The terminal parts 

 of these divisions of the cranial cord are prolonged on the trunk of the internal 

 carotid, and extend to the cerebral and ophthalmic arteries, around which they form 

 secondary plexuses, those on the cerebral arteries ascending to the pia mater. One 

 minute plexus enters the eye-ball with the central artery of the retina. 



Fig. 231. CONNECTIONS OK 



THE SYMPATHETIC NKRVK 

 THROUGH ITS CAROTID 

 BRANCH WITH SOME OK 

 THE CRANIAL NERVES. 



(From Sappey, after 

 Hirschfeld and Leveille.) 



The full description of this 

 ligure will be found at p. 240. 

 The following numbers refer to 

 sympathetic nerves and their 

 connections : 6, spheno-palatine 

 ganglion ; 7, Yidian nerve : 9, 

 large deep petrosal nerve ; 10, 

 a part of the sixth nerve 

 receiving twigs from the carotid 

 plexus of the sympathetic ; 11, 

 superior cervical sympathetic 

 ganglion : 12, its prolongation 

 15, tympanic nerve ; 16, t\vig uniting it to the sympathetic. 



in the carotid branch 



Carotid plexus. The carotid plexus (plexus caroticus inlernus), situated on 

 the outer side of the internal carotid artery at its second bend (reckoning from 

 below), or between the second and third bends, joins the fifth and sixth cranial 

 nerves, and gives many filaments to the vessel on which it lies. 



Branches. (a) The connection with the sixth nerve is established by means 

 of one or two filaments of considerable size, which are supplied to that nerve where 

 it lies by the side of the internal carotid artery. 



(V) The filaments connected with the Gasserian ganglion of the fifth nerve 

 proceed generally from the carotid plexus, but sometimes from the cavernous. 



(c) The large deep petrosal nerve passes forwards from the outer side of the artery 

 to the posterior aperture of the Vidian canal, where it joins the large superficial 

 petrosal from the facial to form the Vidian nerve, which is continued to the spheno- 

 palatine ganglion (p. 243). 



(d) The small deep petrosal nerve passes between the carotid plexus and the 

 tympanic plexus (p. 200). 



Cavernous plexus. The cavernous plexus, named from its position in the 

 sinus of the same name, is placed below and rather to the inner side of the highest 

 turn of the internal carotid artery. Besides giving branches on the artery, it 



