252 ANATOMY IN A NUTSHELL. 



Insertion. — Into the external angle of the base of the arytenoid cartilage 

 in front of the Crico-arytenoideus posticus. 



Action. — T<> contract the glottis by rotating the arytenoid cartilage in- 

 ward. 



\i i;\ e Supply. — Recurrent laryngeal from the pneumogastric. 



Thyro -arytenoideus. 



Origin. — From the side of the angle of the thyroid cartilage and the crico- 

 thyroid membrane. 



[nsertion.- Into the anterior surface and base of the arytenoid cartilage. 



Action. — Relaxes the vocal cords by drawing the arytenoid cartilage for- 

 ward. 



Nerve Supply. — Recurrent laryngeal from the pneumogastric. 



Arytenoideus Muscle. 



Origin. — This is the single muscle of the larynx and comes from the pos- 

 terior surface of the arytenoid cartilage, its fillers running in a transverse direc- 

 tion pass from one cartilage to the other. 



Insertion. — Into the posterior surface of the arytenoid cartilage. 



Action. — It assists in contracting the glottis by approximating the aryten- 

 noid cartilages. 



Nerve Supply. — Recurrent laryngeal from the pneumogastric, and the 

 superior laryngeal. 



Thyro-Epiglottideus. 



Origin. — From the angle of the thyroid cartilage just above the Thyro- 

 arytenoideus. 



Insertion. — Into the lower border of the epiglottis and into the aryteno- 

 epiglottic fold. 



Action. — To compress the sacculus laryngis and to depress the epiglottis. 



Nerve Supply. — Recurrent laryngeal nerve. 



Aryteno-Epiglottideus Superior. 



Origin. — From the tip of the arytenoid cartilage. 



[nsertion. Into the mucous membrane attached to the side of the epi- 

 glottic 



Action. — Contracts the superior opening of the larynx. 

 Nerve Supply. — Recurrent laryngeal. 



Aryteno-Epiglottideus Inferior. 



Origin. — From the anterior surface of the arytenoid cartilage. 



[nsertion.— Into the upper and inner part of the epiglottis. This muscle 

 is separated from the superior muscle by a distinct interval. It is often called 

 the Compressor sacculus laryngis of Hilton. The Triticeo-glottis muscle is a 

 small muscle which is frequently present. Its origin is from the corpus tri- 

 ticeuni, and after passing forward and upward to join the Cerato-glossus, it is 

 inserted into the tongue. 



