406 DIGESTIVE SYSTEM OF THE HORSE 
glosso-pharyngeal, anterior laryngeal, and hypoglossal nerves, the mandibular 
salivary gland, and the parapharyngeal lymph glands. 
The cavity of the pharynx (Cavum pharyngis) presents seven openings. 
Through the posterior nares or choane it communicates dorsally with the nasal 
vavity. The pharyngeal orifices of the two Eustachian tubes (Ostia pharyngea 
Nerves III, 
IV, VI, and 
ophthalmic 
Internal max- Transverse fa- 
illary artery ‘ — eo ‘ Fae bas) a cial —— | 
7 a NeIS, Z / j J TANSVETSE JA= 
Ha pe | ce | 
Buccinator Lateral ptery- 
ene gotd muscle 
Inferior al- 
veolar nerve 
Trternal mazxil- 
lary vein 
Inferior al- Medial pteryoid 
veolar artery muscle 
a Ramus of man- 
Great cornu of, dible 
hyoid bone Hyo-pharyngeus 
muscle 
Lingual branch 
of IX nerve 
External max- 
illary artery 
Hypoglossal 
nerve 
Isthmus faucium 
Tonsil 
Digastricus (in- 
termed. tendon) 
Anterior end of 
Masseteric mandibular gland) 
vessels 
Sublingual vein 
Tianeck corms External maail- | 
4 lary vein | 
of hyoid bone } Omo-hyoidet 
Lymph gland | 
| 
Parotid duct 
Fic. 348.—Cross-secTion oF Heap or Horse. 
The section passes through the anterior part of the temporo-mandibular articulation, but is slightly oblique, passing 
1, Corpus callosum; 2, lateral ventricle of brain; 3, | 
a few millimeters further forward on left side than on right. 
optic chiasma; 7, middle cerebral artery; 8, sphenoidal 
caudate nucleus; 4, internal capsule; 45, lenticular nucleus; 6, 
sinuses; 9, cavernous sinus; 10, Eustachian tube, medial lamina; 71, 17, guttural pouches; 12, soft palate; 13, epi- 
glottis; 14, hyo-epiglottie muscle; 15, thyro-hyoid muscle. The tensor palati (not marked) lies medial to the ptery- 
goideus lateralis, and medial to the tensor is the levator palati, which blends above with the outer lamina of the Eustach- | 
ian tube. 
tubse auditivee) are situated on the lateral wall behind the posterior nares and below 
the level of the ventral nasal meatus. They are slit-like openings, directed ob- 
liquely downward and backward, and are a little more than an inch (ca. 3 cm.) 
in length. They are bounded medially by a fold which encloses the expanded | 
extremity of the cartilaginous Eustachian tube. The isthmus faucium is the oral | 
opening; it is closed by the soft palate except during swallowing. The aditus — 
