VESSELS AND NERVES OF THE LARYNX. 483 



which proceeds from it after it has passed into the cavity of the 

 thorax, and is called from its direction the Recurrent. 



According to M. Blandin, who has rather recently m#de 

 some research upon this subject, the superior laryngeal nerve, 

 is distributed chiefly to the mucous membrane and cryptae of 

 the larynx ; it likewise sends some filaments to the arytenoid 

 and crico-thyroid muscles, and others which anastomose with 

 the branches of the recurrent. The recurrent supplies all the 

 muscles of the larynx, with the exception of the crico-thyroid. 

 There is still among anatomists some difference of opinion in 

 regard to the distribution of these nerves. 



Muscles of the Larynx. 



These are divided into extrinsic and intrinsic. 

 The extrinsic muscles, which are attached by but one extre- 

 mity to the larynx, have been already described. They consist 

 of the sterno-hyoid, omo-hyoid, sterno-thyroid, and thyreo- 

 hyoid ; to which might indeed be added, all the muscles of the 

 supra-hyoid region, and those of the pharynx, which are 

 attached to the cricoid and thyroid cartilages. These, when 

 they act upon the organ, move the entire larynx. 

 The intrinsic muscles, are attached by both extremities to 

 different parts of the larynx, and produce various movements 

 in the different pieces of which it is composed. There are ten, 

 viz., five pairs, and one single muscle which are called the 

 muscles of the chorda vocales, and rima glottidis. Those 

 which exist in pairs are the crico-thyroid, the crico-arytenoidei 

 postici, the crico-arytenoidei lateralis, the thyro-arytenoidei 

 and the arytenoidei obliqui. The single muscle is the aryte- 

 noideus transversus. The oblique and the transverse arytenoid 

 muscles consist, but of a few thin fibres with difficulty distin- 

 guished from each other and are spoken of by many anato- 

 mists, as a common muscle, called simply the arytenoid. 

 There are three other minute muscles, which are called the 

 muscles of the epiglottis, viz. the thyro-epiglottideus, the 

 aryteno-epiglottideus superior, and another muscle lately 

 observed by Mr. Hilton, called aryteno-epiglottideus inferior. 



