ORGANS OF RESPIRATION. 



239 



THE TRACHEA AND BRONCHI. 

 The trachea extends from the cricoid cartilage, a 

 point opposite the lower border of the sixth cervical 

 vertebra, to the level of the intervertebral disc be- 



Thyroid cartilage. 



Crico-thyroid membrane. 

 Cricoid cartilage. 

 Thyroid gland. 



Epartenal 

 bronchus. 



Hyparterial bronchus. 

 Fig. 184. The trachea and bronchi. 



tween the fourth and fifth dorsal vertebrae, extend- 

 ing therefore one to two inches into the chest. The 



