484 



MUSCLE-NERVE PHYSIOLOGY 



Nerve Supply. The sensory filaments of the superior laryngeal branch of the vagus 

 supply the epithelial lining of the larynx, giving it that acute sensibility by which the glottis 

 is guarded against the ingress of foreign bodies, or of irrespirable gases. The contact of 

 these stimulates the nerve endings; and the sensory nerve impulse conveyed to the medulla 

 oblongata, whether accompanied by sensation or not, arouses motor impulses through 

 the filaments of the recurrent or inferior laryngeal branch, which excite contraction of the 

 muscles that close the glottis. Both these branches of the vagi cooperate also in the pro- 



Lig. ary-epiglott. 



Cart. Wrisbergii 

 Cart. Santorini 



mm. Aryten. obliqu. 



m. Crico-arytenoid. post. 



Cornu inferior 



Lig. cerato-cric. 



Pars. post. inf. membrani 

 Pars, cartilag. 



FIG. 345. The Larynx as Seen from Behind. To show the intrinsic muscles 

 posteriorly. (Stoerk.) 



