252 



HANDBOOK OF PHYSIOLOGY. 



cesses of which the production of carbonic acid is the final result. 

 These processes occur in all parts of the body in the substance of the 

 tissues. 



Of the Respiratory Apparatus. 



The object of respiration being the interchange of gases in the lungs, 

 it is necessary that the atmospheric air shall pass into them and that 

 the changed air should be expelled from them. The lungs are contained 

 in the chest or thorax, which is a closed cavity having no communica- 



Fig. 200. 



Fig. 201. 



Fig 200. Outline showing the general form of the larynx, trachea, and bronchi, as seen from 

 before, /i, The great cornu of the hyoid bone; e, epiglottis; t, superior, and t', inferior cornu of the 

 thyroid cartilage; c. middle of the cricoid cartilage ; tr, the trachea, showing sixteen cartilaginous 

 rings; 6, the right, and b', the left bronchus. (Allen Thomson.) X H4- 



Fig. 201. Outline showing the general form of the larynx, trachea, and bronchi, as seen from 

 behind, h, Great cornu of the hyoid bone; i, superior, and t', the inferior cornu of the thyroid 

 cartilage ; e, epiglottis; a, points to the back of both the arytenoid cartilages, which are sur- 

 mounted by the cornicula ; c, the middle ridge on the back of the cricoid cartilage; tr, the pos- 

 terior membranous part of the trachea; 6, 6', right and left bronchi. (Allen Thomson.) x ^. 



