86 HUMAN BIOLOGY 



breath does not come through the nose as quickly as through the 

 mouth ; the lungs are kept more expanded, and one does not get 

 " out of breath " so quickly. (7) The voice of the mouth breather has 

 a hard twang, not a full, resonant tone as when the nostrils are open. 

 (8) Flavors and odors are better appreciated. Sometimes the sense 

 of smell is almost lost by mouth breathers. If one cannot breathe 

 through the nose, even for a short time, there is probably an adenoid, 

 or tonsil-like, growth in nose or pharynx, and a physician should be 

 consulted. " Adenoids " are glandular or grapelike in form. 



Diseases of the Respiratory Organs. A cold or catarrh is an inflam- 

 mation of a mucous membrane. If the inflammation is in the nasal pas- 

 sages, it is called a cold in the head ; if it is in the pharynx, it is called 

 a sore throat ; if it is in the larynx or voice box, there is hoarseness ; 

 if it is in the bronchial tubes, it is bronchitis ; finally, if it is in the air 

 cells, it is pneumonia. If the air is cut off from access to the air cells, 

 there is an attack of the painful disease called asthma, which is accom- 

 panied by a feeling of suffocation. Some believe that asthma is caused 

 by the mucous membrane lining the finest bronchial tubes becoming 

 inflamed and swollen, and closing the tubes ; others think that the 

 muscles in the large bronchial tubes contract and close the tubes. 

 Pleurisy is inflammation of the pleura and makes breathing painful. 

 If much fluid forms between the pleuras, the inner pleura may press 

 upon the lungs and interfere with breathing. 



Alcohol not only weakens the blood vessels near the sur- 

 face, but the blood vessels in general. Weakened and 

 congested blood vessels in the lungs make them more 

 liable to pneumonia and other congestive diseases. Con- 

 tinual congestion causes an abnormal growth of connec- 

 tive tissue fiber in the walls of the cells. This diminishes 

 the capacity of the lungs and interferes with the exchange 

 of carbon dioxid and oxygen. 



Tobacco. It is often asked why cigarettes are so much 

 more injurious to the health than pipes and cigars. The 

 nature of the paper of cigarettes and various other absurd 

 reasons have been assigned. The true reason is that the 

 cigarette smoker usually inhales the tobacco smoke. Cigar 

 smoke, if drawn into the lungs, would usually be coughed 

 up at once. Cigarette smoke is weaker it is so weak 



