134 HUMAN BIOLOGY 



diaphragm is pulled downward toward the horizontal posi- 

 tion. By no other means' are the respiratory organs filled 

 with air, and any interference with the action of either ribs 

 or diaphragm tends to decrease the supply of oxygen and 

 the excretion of carbon dioxid, and to increase the chances 

 of disease in these organs. Tight clothing about the chest 

 and abdomen not only results in permanent distortion of 

 the skeleton (Fig. 46), but also it retards the movements by 

 which the chest cavity is enlarged. Shortness of breath and 

 inability to perform any great amount of muscular exercise 

 are some of the ill effects that are experienced from tight 

 lacing. Diseased conditions of the organs, too, may be 

 brought about when they are thus compressed and forced 

 out of position. It is especially important that loose cloth- 

 ing be worn in the gymnasium, or during any vigorous 

 exercise, in order that the muscles used in motion and respir- 

 ation may be free to work unhampered. 



194. Diseases of the respiratory organs. In 26-34 we 

 discussed the cause, treatment, and prevention of pneu- 

 monia, diphtheria, and tuberculosis, all of which affect the 

 organs of respiration. We shall now call attention to some 

 other diseased conditions often found in these parts of our 

 bodies. Catarrh is an inflammation of the mucous mem- 

 branes of the throat and nose, and it sometimes becomes so 

 bad that these air passages are more or less closed, and it 

 causes a very disagreeable breath. 



. Within the nose and throat cavities projections from the 

 walls frequently develop, which at times practically close 

 these air passages and compel the individual to breathe 

 through the mouth. These are known as adenoids. Be- 

 tween the mouth and throat cavities lie the tonsils; if these 

 become unduly enlarged, and inflammation sets in, tonsillitis 



