BOOK VII. 



Of ike Organs of Respiration. 



THE Organs of Respiration are the Larynx, the Trachea, 



and the Lungs. 



CHAPTER I. 



OF THE LARYNX, 



THE Larynx is an irregular cartilaginous tube that forms the 

 upper extremity of the windpipe. It is situated immediately be- 

 low the os hyoides and the root of the tongue, where it may be 

 felt readily through the integuments, and by its prominence con- 

 tributes to the outline of the neck. Its position is such, that it is 

 bounded behind by the pharynx, which is interposed between it 

 and the vertebrae of the neck; and laterally by the primitive ca- 

 rotid arteries and the internal jugular veins. It gives passage 

 to the air which is inhaled into the lungs or exhaled from them, 

 and also contributes essentially to the production of the voice. 

 Its special use, on the latter occasion, has induced some anato- 

 mists to give it a description apart from that of the other organs 

 of respiration; but as the function of voice is subordinate to 

 that of respiration, I have preferred an observance of its most 

 natural and local connexions. 



Five distinct cartilages form the skeleton of this structure: 



12* 



