ADAPTATIONS 



doings of the Great Sympathetic that 

 physicians do not often mention it because 

 they know so little for certain about it, 

 except that it holds very important re- 

 lations to the chemistry of the living body, 

 while to its nerves is committed the great 

 office of regulating the supply of the blood 

 to every part as it is needed. Thus the 

 stomach needs about nine times more blood 

 when it is digesting than when it is empty. 

 As food enters it, its vasomotor nerves 

 as they are called, which ramify on the 

 coats of the arteries and which are derived 

 from the sympathetic, relax the stomach 

 arteries to flush all its secreting glands, 

 and then when it is empty they shut the 

 supply off. Without this incessant nerv- 

 ous regulation of the blood-vessels we 

 should soon cease to live, because were the 

 great arteries in the abdomen to relax they 

 could hold all the blood of the body. This 

 sometimes occurs with a quickly fatal re- 

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