EFFECTS OF ALCOHOL. 93 



The vaso-constrictor nerves and the vaso-dilator nerves 

 taken together are called Vaso-motor nerves. 



There is no evidence that the sympathetic ganglia are 

 centers of reflex action. 



Let us be alert to discover the action of these nerves as we 

 study other parts of the body. 



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 counteracted 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, STEVENSON and MURPHY. 



" The warm and flushed condition of the skin which fol- 

 lows 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." - Text 

 Book of Physiology, 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, and receives more blood. 



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 becomes per- 

 manent. The circulation in the whites of the eyes may be 

 affected, making them "bloodshot." 



Similar congestion occurs in the mucous membrane of the 

 stomach from the presence of alcohol, which may become a 



