BREATHING 



I6 7 



226. The Movements of Breathing. If we put both hands 

 on the sides of our own chest and breathe* in deeply, 

 we feel that the act has carried the hands farther apart. 

 Again, if we put one hand across the middle of our chest, 

 we feel that it is carried forward every time we breathe 

 in and is returned 

 to its place as we 

 breathe out. 



Again, if we 

 pass a tape meas- 

 ure round the 

 chest and draw it 

 tight when we 

 breathe out, we 

 find that the tape 

 must be let out 

 two or three inches 



as we breathe in. (fT<^\ ^-^^ J I (-B 



If we breathe in 

 and out with a 

 great deal of force, 

 the changes are FlG> I04> 



rrr.r^ t-nor-1r^/l Diagram showing how, as the ribs move upward, the ster- 



IIlUl C IlldlivcCl. f , , . . - . . 



num moves iorward, and increases the size of the chest 



HeilCe there are during inspiration. The first seven ribs are numbered. 

 tWO movements in Dotted lines indicate position in inspiration. A and B 

 indicate the extent of the movement. 



breathing, in one 



of which the cavity of the chest is made larger in all its 

 dimensions. This is when we breathe in air, and it is 

 called inspiration. 



The other movement is the one by which the chest 

 cavity is made smaller. This is when we breathe out air, 

 and it is called expiration. 



