SYSTEMATIC SYNTHESIS OF ORGANS INTO APP. 385 



in inspiration and expiration ; for when the chest is raised 

 above the medium point the cartilages are stretched and 

 tend to restore the thest, causing expiration, and when 

 the chest is drawn below the medium point the natural 

 action of the cartilages tends to restore the chest to the 

 medium point, and inspire air. 



1241. THE MUSCLES OF THE ENTIRE TRUNK- WALLS 

 are at times engaged in respiration, and are divisible 

 into two sets, those of inspiration and those of expira- 

 tion. One set and the diaphragm enlarge the chest, the 

 diaphragm at the same time pressing down all the or- 

 gans beneath it, and of course distending the walls 

 of the abdomen ; then alternately these contract in har- 

 mony with another set of intercostals, and the chest is 

 drawn down at the same time the organs below the dia- 

 phragm are pressed against it relaxed, carrying it up, 

 the elasticity of the lungs expelling the air. 



1242. THUS THE RESPIRATORY APPARATUS MAT BE 



SAID TO INCLUDE a receptacle of air and Blood, with a 

 sub-apparatus on each side, one to drive the latter and 

 the other the former through the receptacle. 



1243. Inf. Respiration affects all the digestory organs, and the 

 more active it is the more pressure there is upon them. 



1244. Remark. Of course all these different parts must act to- 

 gether harmoniously, and all the muscles concerned in the ACTS OP IN- 

 SPIRATION MUST BE DEPENDENT on the same centres for influence to 

 govern their movements. (See pneumo-gastric nerve, PI. 3*.) 



1245. Remark. RESPIRATION is the most important of the Blood- 

 making functions ; related to every organ ; eliminating carbonic acid, 

 that, retained, is an oppressive nervous poison ;" essential to heating the 

 body ; by its abdominal action assisting the activity of the digestory 

 canal ; most likely to be disturbed and to suffer from exposure of the 

 skin. Is it not astonishing that it should be the most neglected and 

 abused of all the functions ? Many forcibly impede, or even constrict 

 it ; most supply it with air, especially during sleeping hours, that is ex- 

 tremely impure, or quite intolerable ; while few so well appreciate its 

 character as to fully realize the importance of its development, often 



1241. What said of ? 1242. What may -? 1243. What said of respiration? 

 1244. on what ? 1245. What farther said of ? 



