LECTURE VIII 



NERVOUS SYSTEM 



Function. — The peculiar function of the nervous system is 

 to control the various organs and systems of the body, and 

 compel them to work in harmony. The peculiar property of 



Fig. 18. — Cerebrospinal Nervous System. 



1, Brain ; 2, optic nerve ; 3, superior maxillary nerve ; 4, inferior maxillary 

 nerve; 5, pneumogastric nerve; 6, spinal cord; 10, radial nerve; 11, median 

 nerve; 12, pneumogastric nerve; 13, portion of solar plexus; 14, solar 

 plexus; 17, sciatic trunk; 19, great sciatic nerve; 20, posterior tibial nerve; 

 21, posterior plantar nerve; 22, internal radial nerve; 23, anterior plantar 

 nerve; 24, digital nerves. 



nerve tissue is irritability. The nervous system is composed of 

 nerve centers, nerves, and nerve cells or neurons. 



A nerve center is composed of nerve cells or neurons with 

 their branches: (a) (axons) — commonly called nerve fibers — 

 over which impulses pass from the cells, and (&) shorter 



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