516 



RESPIEATORY SYSTEM OF THE HORSE 



thjToicl cornu of the hj^oid Ijone; below it is a notch (Fissura thyreoidea), which is 

 converted into a foramen (Foramen thyreoideum) by a fibrous band, and trans- 

 mits the anterior larjmgeal nerve to the interior of the larynx. The posterior comu 

 (Cornu aborale) articulates with the cricoid cartilage. The ventral border joins 

 the body in front, and behind diverges 

 from its fellow to inclose a triangular 

 space, the thyroid notch (Incisura thy- 

 reoidea aboralis), which is occupied by 

 the crico-thyroid membrane. The anter- 



Body 



Median ridge Lamina 



Facet for 

 aryhnoid 



Anterior 

 border 



W\M — Facet for 

 «|l\J ^ thyroid 



Thyroid 

 notch 



i\ rj\ Posterior 



border 

 Arch 



strrior cornu 

 rfnce for 

 cricoid 



Tig. 45S. — Cricoid Cartilage, of Horse; Left Axtero- Fig. 459. — Thyroid Cartilage of Horse; Ventral 



LATERAL \'lEW. ViEW. 



ior border is slightly convex, and is attached to the hyoid bone by the thyro-hyoid 

 membrane. The posterior border overlaps the arch of the cricoid cartilage, and 



Pharyngeal surface 



Medial angle of base Apex 



I sur- 



Cuneiform process 



Fig. 460. — Epiglottic Cartilage of Horse; Right 

 Lateral View. 



Facet 



for 



cricoid 



Vocal process 



Fig. 461. — Left Arytenoid Cartilage of Horse; 

 Medio-ventral View. 



gives attachment to the crico-thyroid muscle. The medial surface is concave, 

 and is partly covered by mucous membrane. 



The epiglottic cartilage (Cartilago epiglottica), usually called the epiglottis for 

 the sake of brevity, is situated above the body of the thyroid cartilage and curves 



