CHAPTER XV 

 RESPIRATION 



Air supply of the body. As we have seen, the 

 venous blood on its return from the tissues must come 

 into contact with the air in the lungs, in order to get 



Vestibule 



Fro. 96. Section of face and neck showing passages of nose, mouth and throat. 

 (Teatut.) 



a fresh supply of oxygen and to remove its burden of 

 carbon dioxide. It is of the utmost importance, there- 

 fore, that the air in the lungs should not fail in purity 

 or abundance. We can live without food for many days, 



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