NERVOUS SYSTEM AND GENERAL SENSATION. 51 



roots of the great arteries that supply the viscera; it possesses 

 motory and sensitive filaments ; through the whole of its. ex- 

 tensive course it confers sensibility on the vocal and respira- 

 tory organs, and on the stomach. 



[ 1 06. The Spinal Accessory ( 1 2) is seen ascending along the 

 spinal cord, and passing backwards beneath the cerebellum. It 

 is distributed principally to the great respiratory muscles, and 

 is a motory nerve. 



[ 107. The Lingual Nerve (11) is the motory nerve of the 

 tongue, special sensibility being imparted to that organ by the 

 fifth pair, common sensation by the glosso-pharyngeal, and 

 motion by the lingual. It guides the muscles of the tongue in 

 the various operations of chewing, swallowing, and articulating, 

 as often as that organ comes into play in the latter act. 



[ 108. The Spinal Nerves, we have already shown ( 90), 

 unite with the spinal cord by two roots. The posterior roots 

 are furnished with ganglia, over which the primary fasciculi 

 of the anterior roots pass without mixing. Immediately be- 

 yond the ganglia, the primary fibres of both roots blend 

 together, and form compound nerves. At 14 and 15 (fig 20), 

 the two first pairs of spinal cervical nerves are seen : these 

 enter into combination with several cerebral nerves. Their 

 sensitive fibres supply the skin of the occiput, ear, chin, and 

 cheek, and send motory fibres to several of the muscles of the 

 tongue. The phrenic nerve chiefly derived from the fourth 

 cervical, although it obtains filaments from other nerves, is 

 distributed to the diaphragm, and regulates the involuntary 

 respiratory movements effected by the rising and falling of that 

 muscle. The general distribution of the other spinal nerves 

 has been indicated in our outline 'of fig. 19. 



[ 109. The Great Sympathetic Nerves are placed along the 

 sides of the vertebral column, and extend from the base of the 

 skull to the os coccyx. They may be said to consist of a chain 

 of ganglia, communicating with all the cerebral and spinal 

 nerves, those of the three higher senses excepted. They are 

 destined to preside over the processes of nutrition, and have 

 their great centre, the solar plexus, situated in the abdomen; 

 from the ganglia of the sympathetic, branches proceed to the 

 heart and blood vessels, the lungs and air passages, the stomach 

 and intestinal canal, the liver, kidneys, and other glands. From 

 this distribution of the sympathetic nerves, to the organs sub- 



E 2 



