250 HUMAN ANATOMY. 



aryteno-epiglottidean fold ; action, compress the sacculus laryngis 

 and depress the epiglottis; nerve, recurrent laryngeal. 



Arytceno-epiglottideus superior. Origin, from apex of 

 arytenoid; insertion, into aryteno-epiglottidean folds; action, 

 constricts the superior laryngeal aperture; nerve, recurrent 

 laryngeal. 



Arytceno-epiglottideus inferior. Origin, from middle of in- 

 ternal portion of the arytenoid ; insertion, into upper and inner 

 part of epiglottis; action, compresses the sacculus laryngis; 

 nerve, recurrent laryngeal. 



The lining mucous membrane of the larynx is continuous 

 with that of the pharynx and trachea. It forms the glosso- 

 epiglottic and arytseno-epiglottic folds, adheres tightly to the 

 epiglottis, vocal cords, and the interior of the cricoid cartilage, 

 but is more loosely attached to other parts. It contains numer- 

 ous racemose glands, particularly along the posterior margin of 

 the arytaeno-epiglottidean fold, and in front of the arytenoid car- 

 tilages, where they are called the arytenoid glands. Its epithe- 

 lium is of the ciliated, columnar variety below the true vocal 

 cords, and above this point in front as high as the middle of 

 the epiglottis. The other portions are covered by squamous 

 epithelium. 



The arteries are the laryngeal branches from the superior 

 and inferior thyroid, and the crico-thyroid branches of the supe- 

 rior thyroid. 



The veins join the inferior, middle, and superior thyroid 

 veins. 



The lymphatics enter the deep cervical glands. 



The nerves are the inferior or recurrent laryngeal, the supe- 

 rior laryngeal branches of the pneumogastric, and branches from 

 the sympathetic nerve. 



The superior laryngeal supplies sensation to the larynx. It 

 descends from the inferior ganglion of the pneumogastric, behind 

 the internal carotid at the side of the pharynx, and divides into 

 two branches the internal laryngeal pierces the thyro-hyoid 

 membrane to supply the mucous membrane and arytenoid muscle, 

 the external laryngeal supplies the crico-thyroid muscle. 



The inferior or recurrent laryngeal, from its origin, winds 

 around the subclavian on the right side and around the arch of 

 the aorta on the left side, and ascends by the side of the trachea 

 to the larynx, of which it is the motor nerve, supplying all the 

 muscles of the larynx except the crico-thyroid, giving off in its 

 course cardiac, oesophageal, tracheal, and pharyngeal branches, 

 and anastomosing with the superior laryngeal nerve. 



