CHAPTER XL 



THE NERVES. 



The nerves are highly specialized fibers, beginning in 

 a cell and ending in a special end-organ. Their func- 

 tion is to carry impulses to and from the cell. The 

 combination oi a cell, end-organ, and nerve fiber, is 

 called a neuron. A nerve cell is one of the largest cells 

 in the body and possesses all the essentials of any 

 cell, viz. : nucleus, nucleolus and protoplasm. They 

 have no cell wall. The cells vary greatly in shape, and 

 each point of the cell is called a pole. One of the points 

 is called an axis cylinder. The points arising from the 

 cell at other points than the one called axis-cylinder 

 are called dendrites. The nerves are named according 

 to the number of processes they have. The first type 

 and second type cells are those cells that have either a 

 long or short axis cylinder. The first is a first type 

 cell, and the second is a second type cell. Neurogha 

 cells are small cells that give off several short proc- 

 esses, which act as a connective tissue. The cell is 

 called a glia cell, and the fibrils are called neuroglia. 

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