Area of Lungs 



193 



chest, just in front of the vertebral column, as much lung is found 



behind as in front of it. It is this 



thick posterior part which becomes 



sodden when a feeble person is 



kept long in bed in the supine 



position Jiypostatic pneumonia. 



Even after the deepest expira- 

 tion about 200 cubic inches of 

 ' residual ' air, H, remain in the 

 lungs ; for convenience, another 

 loo cubic inches are 'reserved' in 

 ordinary respiration, the * tidal ' air 

 amounts to about 50 cubic inches 

 more, and when an additional 100 

 cubic inches of 'complemental' air 

 are inspired the lungs are full to 

 the utmost. 



To mark the anterior border 

 of the lungr. From the apices (p. 164) the anterior borders of the lungs 



Complemental air 



Tidal 



Reserved 



Residual 



(HUTCHINSON.) 



Area of lungs shaded ; heart in outline. (HOLDEN.) 



