RESPIRATION 



43 



the lower part of the pharynx* the air leaves it and 

 enters the larynx through an opening called the glottis. 

 The top of the larynx is guarded by a trapdoor (epi- 

 glottis) which closes the glottis in the act of swallowing, 

 and so prevents food and drink from entering the air 

 tubes leading to the lungs. 



FIG. 16. Larynx, trachea, and bronchi. From Heitzmann's "Anatomy" 

 (Becker). 



The larynx (voice box) is a very delicately constructed 

 organ, serving both as a passage for air and as the 

 organ for producing voice. It is a very useful organ 

 and will be described more fully in a later chapter. 



47. The Trachea and Bronchial Tubes. The larynx 

 ends below in the trachea, or windpipe, which is a tube 



