SYSTEM OF THE GREAT SYMPATHETIC. 



515 



Fig. 166. 



motor filaments from the facial nerve, by means of the chorda 

 tympani. Its branches of distribution pass to the sides of the tongue 

 and to the submaxillary and sublingual glands. 



The last sympathetic ganglion in the head is the otic ganglion. 

 It is situated just beneath the 

 base of the skull, on the inner 

 side of the third division of 

 the fifth pair. It sends fila- 

 ments of communication to 

 the carotid plexus; and re- 

 ceives a motor root from the 

 facial nerve, and a sensitive 

 root from the inferior maxil- 

 lary division of the fifth pair. 

 Its branches are sent to the 

 internal muscle of the mal- 

 leus in the middle ear (tensor 

 tympani), and to the mucous 

 membrane of the tympanum 

 and Eustachian tube. 



The continuation of the 

 sympathetic nerve in the neck 

 consists of two and some- 

 times three ganglia, the su- 

 perior, middle, and inferior. 

 These ganglia communicate 

 with each other, and also 

 with the anterior branches 

 of the cervical spinal nerves. 

 Their filaments follow the 

 course of the carotid artery 

 and its branches, covering 

 them with a network of inter- 

 lacing fibres, and are finally 

 distributed to the substance of 

 the thyroid gland, and to the 



,, , , 



walls of the larynx, trachea, 



pharynx, and oesophagus. 



By the superior, middle, and inferior cardiac nerves, they also supply 



sympathetic fibres to the cardiac plexuses and to the substance of 



the heart. 



Conrse and distributi n of the GREAT STMPA- 



