110 



RESPIRATION RESPIRATORY MOVEMENTS. 



PHYSIOLOGICAL ANATOMY OF THE RESPIRATORY ORGANS. 



Passing backward from the mouth to the pharynx, two openings are 

 observed ; a posterior opening, which leads to the oesophagus, and an ante- 

 rior opening, the opening of the larynx, which is the beginning of the pas- 

 sages concerned exclusively in respiration. 



Beginning with the larynx, it is seen that the cartilages of which it is 

 composed are sufficiently rigid and unyielding to resist the pressure produced 

 by any inspiratory effort. Across its superior opening are the vocal chords, 

 which are four in number and have a direction from before backward. The 

 two superior are called the false vocal chords, because they are not concerned 

 in the production of the voice. The two inferior are the true vocal chords. 

 They are ligamentous bands covered by folds of mucous membrane, which is 



FIG. 39. Trachea and bronchial tubes (Sappey). 



1, 2, larynx ; 3, 3, trachea ; 4, bifurcation of the trachea ; 5, right bronchus : 6, left bronchus ; 7, bron- 

 chial division to the upper lobe of the right lung ; 8, division to the middle lobe ; 9, division to the 

 lower lobe ; 10, division to the upper lobe of the left lung ; 11, division to the lower lobe ; 12, 12, 12, 

 12, ultimate ramifications of the bronchia; 13, 13, 13, 13, lungs, represented in contour; 14, 14, summit 

 of the lungs ; 15, 15, base of the lungs. 



quite thick on the superior chords and very thin and delicate on the true 

 vocal chords. These bands are attached anteriorly to a fixed point between 



