70 PHYSIOLOGY. 



But this mechanism for widening the channel leading to 

 the working organs, while the arteries to the other organs 

 are made smaller, or at least are not enlarged, solves the 

 problem of supplying each part according to a greatly 

 varying need, while not sending too much to a part not 

 needing it. 



EFFECTS OF ALCOHOL ON THE CIRCULATION. 



" Alcohol stimulates the heart, producing increased force 

 and rapidity of the cardiac beat. It thus tends to increase 

 the blood pressure by acting on the heart, and to increase 

 the flow of blood from the arteries into the veins. The 

 effect on the blood pressure is, however, partly counter- 

 acted by a coincident dilatation of the blood vessels of the 

 skin, which thus become flushed, and tends to produce 

 more sensible perspiration." Treatise on Hygiene, STE- 

 VENSON and MURPHY. 



"The warm and flushed condition of the skin which 

 follows the drinking of alcoholic fluids is probably, in a 

 similar manner, the result of an inhibition of that part 

 of the vaso-motor center which governs the cutaneous 

 arteries." FOSTER. 



The control of the muscles in the walls of the arteries 

 being thus interfered with, the circular muscles are no 

 longer made to shorten, and the artery dilates, thus allow- 

 ing more blood to flow into it. 



We may thus account for the flushing of the skin of the 

 face, which in many individuals quickly betrays indulgence 

 in alcoholic drink. If this flushing is too often repeated, 

 the arteries gradually "lose tone," and the condition be- 

 comes permanent. The circulation in the whites of the 

 eyes may be affected, making them "bloodshot." 



