ANATOMY IN A NUTSHELL. 



251 



LESSON LXIX. 

 Cricothyroid Muscle. 



Origin. — From the side of the cricoid cartilage. 



Insertion. — Into the interior border and lower cornu of thyroid cartil 

 age. 



Action. — Rotates the posterior part of cricoid cartilage downward and 

 backward, and thus tightens the vocal cords. 



Nerve Supply. — External laryngeal from the superior laryngeal. 



Blood Supply. — The superior laryngeal from the superior thyroid, and 

 the inferior larvngeal from the inferior thyroid. The veins have the same name 



PLATE CTI. 



ANTERIOR LONGITUDINAL 

 WENINGO-RACHIDIAN. 



POSTERIOR LONGITUDINAL. 

 YENINCO-RACHIDIAN 



VENAE BASIS VERTEBRARUM 



Veins of Spinal Cord axd Column (Sagittal View.) 



as the arteries and accompany them. This is the blood supply of all the mus- 

 cles of the larynx. 



Crico-arytenoideus Posticus. 



Origin. — From posterior surface of the cricoid cartilage. 



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



Action. — It dilates the glottis bv rotating the arytenoid cartilage out- 



ward. 



Nerve Supply'. — Recurrent laryngeal from the pneumogastric nerve. 

 Crico-arytenoideus Lateralis. 



Origin. — From the upper border of the sides of the cricoid cartilage. 



