90 



THE MECHANISM OF LIFE 



the spinal cord there issue out spinal nerves, one pair at each 

 joint of the vertebral column. These also consist of fibres going 

 to and coming from the body, limbs, and skin. Along either 

 side of the vertebral column are other two series of outlying nerve 

 ganglia which form the sympathetic nervous system, and these 



jL 



Cerebellum 

 cervica.! 



Sympathetic 



chain of: ^ 

 ^ari^lio. 



brachial 

 , bleycus 

 (V-Ylicerv 

 JdLorsa.1 ) 



Jhrsal 

 ^ sfiinal 

 nerves 



Fig. 21. — A General Diagram op the Central Parts of the Human 

 Nervous System. 



The sympathetic ganglia and their main connections with the spinal 

 nerves are represented in black. 



ganglia are all connected with the spinal nerves by communi- 

 cating branches. Most people are familiar with the " solar 

 plexus," which is an important part of the sympathetic nervous 

 system. The cranial nerves go mainly to the muscles of the face 

 and eyes, or come from the great sense organs of the head. The 



