216 MICROBES AND HEALTH. 



The question is of small importance, however, for back 

 of all is a lack of nourishment caused by indigestion. 

 Exposure, over-exertion or injury may also be respon- 

 sible for some cases of spinal disease. 



Practically all forms of paralysis are the same. They 

 consist of increased blood-supply, the result of inflam- 

 mation, followed by degeneration of the nerves and 

 nerve-cells, an overgrowth of connective tissue which 

 contracts and hardens. Sometimes one part of the 

 cord is affected, sometimes another. 



A nerve is no more or less than a long drawn out 

 process of a nerve-cell. Certain cells in the brain and 

 spinal cord send out these prolongations, and thus the 

 nervous system is formed. 



The nerves of sensation arise in the back part of the 

 cord, hence inflammation of this part is first indicated 

 by increased sensibility, which may be in the form of 

 pain, numbness, or tingling sensations. Later there is 

 loss of sensation, showing that the destruction is more 

 complete. 



The nerves of motion arise in the front part of the 

 cord, hence inflammation of this part, acting as a stim- 

 ulant, is first indicated by increased muscular action. 

 This is 'followed by loss of motion and shrinking of the 

 muscles, showing destruction and degeneration of this 

 system. 



The voluntary muscles of the body and extremities 

 are supplied with nerves from the spinal cord. Many 

 of the nerves arising in the brain extend downward, 

 connect with the spinal nerves and modify or control 



