THE AIR-PASSAGES. 



235 



(Fig. 41) is an aperture through which it passes into the 

 larynx or voice-box (a, Fig. 64), which lies in the upper 

 part of the neck. From the larynx air passes on through 

 the windpipe or trachea; this enters the chest, in the upper 



FIG. 64. 



FIG. 65. 



FIG. 64. The lungs and air-passages seen from the front. On the left of the 

 figure the pulmonary tissue has been dissected away to show the ramifications 

 of the bronchial tubes, a, larynx ; 6, trachea; d, right bronchus. The left bron- 

 chus is seen entering the root of its lung. 



FIG. 65. A small bronchial tube, a, dividing into its terminal branches, c,' 

 thes ) have pouched or sacculated walls and end in the sacculated alveoli. 6. 



* 



part of which it divides into a right and a left bronchus. 

 Each bronchus enters a lung, and divides in it into & vast 

 number of very small tubes, called the bronchial tubes. 

 The last and smallest bronchial tubes (a, Fig. 65) open 

 into subdivided elastic sacs, ~b, c, with pouched walls. 



What aperture is found on the ventral side of the pharynx? 

 Where does the larynx He? Where does the air go from the larynx? 

 Into what does the trachea divide? Where? What are the bronchial 

 tubes? How do the final bronchial tubes terminate? 



