PHONATION; ARTICULATE SPEECH 683 



believed that these fibers are derived originally from the efferent fibers of the 

 glosso-pharyngea* nerve. The remaining fibers of the superior laryngeal 

 endow the upper portion of the larynx with extreme sensibility which to a 

 certain extent protects the air-passages against the entrance of foreign 

 bodies. Irritation of the terminal filaments of this nerve by particles of 

 food, solid or liquid, gives rise to marked reflex spasm of the adductor 

 muscles and closure of the glottis, followed by a strong expiratory blast of air 

 from the lungs by which the offending particles are removed. Division of 

 this nerve on both sides is followed by a paralysis of the crico-thyroid muscles, 

 a lowering of the tension of the vocal bands, and a loss of sensibility of the 

 laryngeal mucous membrane. 



