MUSCLES OF THE LARYNX. 



485 



Inserted into the side of the base of the arytenoid cartilage 

 near the former. 



Use. To open the rima glottidis, by pulling the ligaments 

 from each other. 



Fig. 123.* 



4. Thyreo-Arytanoideus, 



Arises from the under and back part of 

 the middle of the thyroid cartilage ; and, 

 running backwards and a little upwards, 

 alo.ig the side of the glottis, is 



Inserted into the arytenoid cartilage, 

 higher up and farther forwards than the 

 crico-arytaenoideus lateralis. 



Use. To pull the arytenoid cartilage 

 forwards nearer the middle of the thyroid, 

 and consequently to shorten and relax the 

 ligament of the larynx or glottis vera. 



5. Arytanoideus Obliquus, 



Arises from the base of one arytenoid cartilage ; and crossing 

 its fellow, is 



Inserted near the tip of the other arytenoid cartilage. 



Use. When both act they pull the arytenoid cartilages towards 

 each other. 



N. B. One of these is very often wanting. 



The single muscle is, the 



Arytanoideus Transversus, 



Arises from the side of one arytenoid cartilage, from near its 

 articulation with the cricoid to near its tip. The fibres run 

 straight across, and are 



Inserted, in the same manner, into the other arytenoid car- 

 tilage. 



* A posterior view of the larynx. 1. The thyroid cartilage. 2. One of its 

 ascending cornua. 3. One of the descending cornua. 4. 7. The cricoid carti- 

 lage. 5, 5. The arytenoid cartilages. 6. The arytenoideus muscle, consisting 

 of oblique and transverse fasciculi. 7. The crico-arytenoidei postici muscles. 

 8. The epiglottis. 



41* 



