HEAD AND NECK OF THE HORSE 



103 



The character of the articulation between other cartilages, and the 

 union of the two arytenoid cartilages, may now be more easily 

 determined. 



The base of the epiglottis is attached to the thyroid cartilage by 

 the thick and elastic thyro-epiglottic ligament (ligamentum thyreo- 

 epiglotticuni), which, in conjunction with the elasticity of the epiglottis 

 itself, permits of free movement. 



Now that the restraining muscles have been removed, it is easy 

 to demonstrate that the movement between the thyroid cornua and 



N. glossopharyngeus. 



A. maxillaris externa. 



M. stylohyoideus. 



N. hypoglossus. 



M. digastricus. 



M. pterygoideus internus. 



N. laryngeus cranialis. 



"Ventricular fold. 



Appendix of ventricle. 



Submaxillary gland. 



Parotid duct. 

 V. maxillaris externa. 



Mm. sternohyoideus 

 et omohyoideus. 



_ -Wall of pharynx. 



--Corniculate cartilage. 

 Pharyngo-palatine arch. 



Aryepiglottic fold. 



Cuneiform cartilage. 

 Thyroid cartilage. 

 M. ventricularis. 

 .Vocal fold. 

 M. thyreohyoideus. 

 M. vocalis. 



''' Lig cricothyreoideum. 



Fig. 41. — Transverse section of the larynx and pharynx. 



the cricoid cartilage is rotatory about a transverse axis running 

 through the joints of opposite sides of the larynx. 



The crico-arytenoid joint is also diarthrodial. Its movements are 

 gliding in various directions, and (more important because of the 

 adduction and abduction of the vocal folds thus produced) rotatory 

 about a longitudinal axis. It should be noted that the capsule of 

 the joint is strengthened medially. 



The medial angles of the two arytenoid cartilages are united by 

 a narrow band of fibrous tissue (ligamentum arytsenoideum trans- 

 versum) that is sufficiently loose to allow of the necessary rotation 

 in the crico-arytenoid joint. 



Dissection. The dissector should now transfer his attention to the 



occipital region. The occipital and temporal attachment of the brachio- 

 cephalic and splenius muscles must be liberated from the bone, and the 

 short muscles dorsal to the atlas and epistropheus cleaned and defined. 



