226 



OUR BODIES AND HOW WE LIVE 



distributed, that is, those parts 

 The case is not unlike that of 

 and thus stopping the passage 



FIG. 142. The Cervical and Thoracic 

 Portions of the Sympathetic Nerve and 

 their Main Branches. 



In the center of the figure, running almost 

 vertically, is shown the right pneumogastric 

 nerve. To the left may be seen a chain of 

 ganglia of the sympathetic nerve, running 

 along the vertebrae. The distribution of 

 some smaller ganglia and nerve branches in 

 the neck and chest regions are also shown. 



of the body are paralyzed. 



cutting a telegraph wire, 



of the electric current. 



304. The Sympathetic 

 Nervous System. The 

 sympathetic nervous sys- 



, tern, 1 as we have learned 

 (Sec. 289), consists of a 

 double chain of nerve 

 knots, or ganglia, con- 

 nected by nervous cords 

 running down in front 

 and on each side of the 

 backbone. 



The knots of nerves 

 are connected with each 

 other, and with the spinal 

 nerves, by a network of 

 nerve fibers. 



Through the sympa- 

 thetic ganglia, nerve 

 fibers from a part of 

 each spinal nerve pass 

 on their way to impor- 

 tant internal organs. A 

 close network of the 



1 The name " sympathetic " 

 was given to this part of the 

 nervous system because it was 

 believed that, through its 

 agency, distant organs have 

 sympathy with one another's 

 afflictions. 



