

THE ADKENAL GLANDS 83 



such processes as contraction and dilation, secre- 

 tion, and various nutritional processes. 



In their action the sympathetic nerves are often 

 antagonistic to the cranial ones. The stimulation 

 of the latter stops the heart beat; the stimulation 

 of the sympathetic fibers quickens the heart beat. 

 So, indeed, does adrenaline : its action is to quicken 

 the heart beat. 



It would be difficult to name a substance used in 

 medicine that has proved of greater value than 

 adrenaline. It causes a contraction of the arteries 

 and is an excellent hemostatic, that is, it checks 

 the flow of blood. In shock and collapse, often fol- 

 lowing surgical operations, the procedure adopted 

 by Crile, the well-known Cleveland surgeon, of 

 administering adrenaline solutions, has been gen- 

 erally adopted. Though we know little as to the 

 cause and nature of shock, 1 we do know that in 

 such a condition the arteries contain less blood, 

 and the veins more blood than usual. Since adrena- 

 line constricts the arteries, its use under these con- 

 ditions provokes attempts on the part of the body 

 to restore equilibrium. 



The suggestion has been made that trench life in 

 war leads to depression of adrenal activity, and 

 that this is connected with the clinical picture of 

 shock in war. We shall return to this later. 



It might be expected that cases of hemorrhage,. 



*For further information see Chapter XII. 



