HEAD AND NECK OF THE HORSE 



69 



The cavity of the pharynx (cavum pharyngis) is divisible into dorsal 

 and ventral portions, the plane of separation being indicated by the free 

 edge of the soft palate and the pharyngo-palatine arch, these bound- 



Parotid gland. , 



Eustachian tube 



Hyoid bone. 



M. tensor veli palatini. 



M. jugulomandi- 



bularis. 



M. pterygoideus internus. 



M. pterygopharyngeus,, 



M. stylo-. 



pharyngeus. 



M. palato- 



pharyngeus. 



A. maxillaris 

 externa. 



N. laryngeus 

 cranialis. 



M. crico- 

 pharyngeus.' 



A. pharyngea 

 ascendens. 



Thyroid gland 



V. jugularis. 



CEsophagus. — 



A. maxillaris 

 interna. 



A. temporalis 

 superficialis. 



A. carotis 

 externa. 



V. maxillaris 

 interna. 



N. glosso- 



pharyngeus. 



N. hypoglossus. 

 A. carotis 



externa. 

 Submaxillary 



gland. 

 A. occipitalis. 

 A. carotis 



interna. 



V. occipitalis. 



A. carotis 

 communis. 



A. thyreoidea 

 cranialis. 



I ^ Trachea. 



Fig. 20. — Dorsal aspect of the pharynx, &c., after removal of the vertebral column 

 and the occipital part of the skitll. 



ing an oval pharyngeal isthmus that forms a communication between 

 the two parts. The dorsal part (pars respiratoria) communicates with 

 the nasal cavities by the choanaj, and is purely respiratory in function. 

 In the middle line, behind the openings of the auditory tubes, there is a 

 variable blind pharyngeal recess (recessus pharyngeus) that is protruded 



