346 PRACTICAL ANATOMY. 



mucous membrane lining the larynx. Below the false 

 are the true vocal cords, formed of yellow elastic tissue 

 and invested by mucous membrane. They are attached 

 closely together in the receding angle of the thyroid car- 

 tilage ; they pass horizontally backward and are inserted 

 on the anterior angles of the arytenoids ; each vocal cord 

 is about one-sixth of an inch wide and about five-eighths 

 of an inch long, but susceptible, by virtue of its elas- 

 ticity, of considerable elongation. Between the false 

 and true vocal cords is the ventricle of the larynx, a 

 depression which communicates with the sacculus laryn- 

 gis, a large mucous crypt ; upon its surface the fibres of 

 the inferior thyro-epiglottic muscles are distributed. 

 The mucous membrane of the larynx continues with that 

 of the trachea, mouth, and pharynx, is reflected over all 

 the structures in the larynx. On the true vocal cords 

 it is very thin and tightly adherent; above the false 

 cords it is covered principally by squamous epethelium ; 

 below, it is of the ciliated variety. 



THE TRACHEA. 



The trachea, or wind-pipe, is a membrano-cartilagi- 

 nous, cylindrical tube about five inches long, and ex- 

 tends from the fifth cervical to the third dorsal vertebra. 

 It is about three-fourths of an inch in diameter, and 

 terminates below in the right and left bronchi. The 

 right is short, wide, and nearly horizontal in direction ; 

 the left is long, narrow, and oblique. If a section be 

 made just above the bifurcation of the trachea, a septum 

 is observed to extend upward between the two bronchi; 

 it inclines to the left ; in fact, it looks as if the right 

 bronchus were continued or thrust into the trachea. This 

 arrangement explains the tendency of foreign bodies to 

 lodge in the right bronchus. The trachea consists of 



