I 10 



Physiology. 



diseases are found wherever people are crowded into ill- 

 ventilated rooms, we can realize the force of the statement, 

 " Man's own breath is his worst enemy." 



Summary of Respiration. The tissues need oxygen ; 

 air is pumped into the lungs ; this air gives oxygen to the 

 blood ; the blood carries it to the tissues. 



In oxidizing, the tissues produce energy (heat and 

 motion) and give off waste matter (water, carbon dioxid, 

 etc.); these the blood carries to the lungs, the lungs give 

 them to the air, and the air carries them out of the body. 



The pumping of the air in and out and the exchanges 

 between the air and the blood in the lungs may be called 

 "external, or mechanical respiration." The action of the 

 oxygen of the blood in the tissues is the " real, or internal 

 respiration." 



Effect of Alcohol on Internal Respiration. Alcohol is 

 easily oxidized. This is shown in the readiness with which 

 alcohol burns and the amount of heat it produces in burn- 

 ing. Alcohol, to a certain extent, may be oxidized in the 

 body. But it is not useful on this account. For, while it 

 produces some heat, it causes much more heat to be lost 

 by the greater flow of blood in the skin. When alcohol 

 is oxidized in the body, so much oxygen is taken that the 

 blood has not enough left for the needed oxidation in the 

 tissues where work is to be done. The consequent lack of 

 oxygen through the body weakens it everywhere. Not only 

 is there a shortage in the supply of oxygen, but there is an 

 over-amount of carbon dioxid. Much of the carbon dioxid 

 which should have left the blood in the lungs remains, and 

 does great harm. For blood with a surplus of carbon dioxid 

 injures the tissues, and they all suffer. This condition of 

 the blood too much carbon dioxid and too little oxygen 



