HUMAN PHYSIOLOGY 



CHAP. 



FIG. 14. Cili- 

 ated cells 

 from the nose 

 (Zinns) . 



fp/g/ott/s 



and foreign substances by means of its 

 hairs and hairlike cilia. Besides doing 

 all this, the nose is the organ of smell. 

 Little nerve endings are found in the 

 mucous membrane of the upper part of 

 the nose, that enable us to smell. 



Why should we breathe through the 

 nose rather than through the mouth ? 

 The nose warms, moistens, and purifies 



the air and is the natural channelmade for breathing. 



If persons breathe through the mouth, they cannot de- 

 tect foul air by its odor ; the mucous membrane of the 



mouth and throat become dry ; cold, dry air reaches 



the delicate tissues of the 



lungs, where it is sure to 



cause discomfort and even 



disease ; and all the fine 



particles of dust and dirt 



floating about in the air 



pass down into the lungs. 



We should always breathe 



through the nose. 



46. The Pharynx and 



Larynx. After passing 



through the two nostrils 



the air enters the pharynx. 



This is a rather large fun- 

 nel - shaped organ that 



serves as a reception hall 



for both air and foods. At FIG. 15. Larynx (Zuppke). 



