EESPIRATION 507 



half-way toward expiration. Suddenly open the 

 respiratory passage. 



Air is quickly and forcibly expelled from the 

 lung (cough, sneeze). 



. Hiccough. Lower the diaphragm quickly 

 toward full inspiration, and while the lung is 

 expanding close the respiratory opening with 

 the moistened thumb (hiccough). 



Note the sudden changes of pressure in the 

 two cavities. 



Perforation of the Pleura. Open the inlet to 

 the pleura. 



Note the effect of the opening into the pleural 

 cavity upon the lung and upon the intra-pulmo- 

 nary and intra-thoracic pressure. 



Observe the result of movements of the 

 diaphragm^ 



