The Blood and its Circulation 1 5 7 



238, First Effect of Alcohol upon the Circulation. When 

 alcohol is taken in moderate quantities by a person in health 

 the pulse beats faster and usually less regularly, the circu- 

 lation becomes more rapid, and the blood passing rapidly 

 through the tissues yields to them less of its oxygen. 

 From this it is evident that under these conditions the 

 blood is not doing its full work. 



This early stage in the action of alcohol lasts for only 

 a short time, and is followed by a reaction in which the 

 strength and rapidity of the 

 heart beats fall even below the 

 point at which they were working 

 when the dose of alcohol was 

 given. Thus the total amount of 

 work done at the end of a given 

 period is no greater than if the 

 alcohol had not been given 

 at all. 



Owing to the increased demand FlG ; 82 ' circulation in the 



Capillaries, as seen with 



made on the wall of the heart the Microscope, 

 during the period of increased 



activity, the heart itself is in a distinctly worse condition 

 than it would have been if the increased strain had 

 not been put upon it in consequence of the action of 

 the alcohol. 



239. Further Effect of Alcohol upon the Circulation. The 

 inhibitory nerves, as we have seen, exercise a restraining 

 control orer the heart and the arteries, very much as the 

 reins control a running horse. In health this inhibitory 

 influence is protective and sustaining. When alcohol 

 is taken, these inhibitory nerves are partially paralyzed, 

 because the narcotic has had its effect upon that part of 

 the vaso-motor center which governs them. 



