RESPIRATORY MOVEMENTS. 



197 



the junction of the latter with their cartilages, make the 

 effect much greater at the lower than at the upper part of 

 .the chest. 



Fig. 63.* 



X f 



The expansion of the chest in inspiration presents some 



* Fig. 63 (after Hutcliinson). The changes of the thoracic and 

 .abdominal walls of the male during respiration. The "back is supposed 

 to be fixed in order to throw forward the respiratory movement as much 

 as possible. The outer black continuous line in front represents the 

 ordinary breathing movement: the anterior margin of it being the 

 boundary of inspiration, the posterior margin the limit of expiration. 

 The line is thicker over the abdomen, since the ordinary respiratory 

 movement is chiefly abdominal : thin over the chest, for there is less 

 movement over that region. The dotted line indicates the movement 

 on deep inspiration, during which the sternum advances while the 

 abdomen recedes. 



t Fig. 64 (after Hutchinson). The respirator} movement in the female. 

 The lines indicate the same changes as in the last figure. The thickness 

 of the continuous line over the sternum shows the larger extent of the 

 ordinary breathing movement over that region in the female than in 

 the male. 



