EESPIRATOEY SYSTEM OF THE OX THE NASAL CAVITY 



537 



RESPIRATORY SYSTEM OF THE OX 



THE NASAL CAVITY 



The nostrils (Fig. 379), situated on either side of the muzzle, are relatively 

 small, and are much less dilatable than those of the horse. The alae are thick and 

 firm. The superior commissure is narrow. There is no diverticulum nasi. The 

 skin is smooth, bare, and moist, and there is no clear line of demarcation between 

 it and the nasal mucosa. The opening of the naso-lacrimal duct is not visible, as 



ital eminetice — 



Great ethmo-turbinate 



Dorsal turbinate 



Dorsalmeatus 

 Middle meatus 



Ventral 

 turbinate 



Ventral 

 meatus 



Naso- 

 labial 

 glands 



Body of 

 mandible 



Genio- Mylo-hy- Genio- 

 glossus oideus hyoideus 



Thyroid cartilage 



Fig. 476. — Sagittal Section of Head of Cow. 

 ^, Cerebral hemisphere; ^, lateral ventricle; 3, thalamus; 4. corpora quadrigemina; (5, optic chiasma; 5, pituitary 

 body; 7, pons; 5, medulla oblongata; 9, cerebellum; 10, spinal cord; 11, ventral straight muscles; 13, pharyngeal 

 lymph gland; iS, arytenoid cartilage; 7^, epiglottis; -?5, cricoid cartilage; i6', vocal cord; i 7, palatine sinus; ^5, soft 

 palate; 19, Eustachian opening; CI, C2, C3, first, second, and third cervical vertebra; B.o., basioccipital ; Sp., pre- 

 sphenoid. 



it is on the lateral wall of the nostril, and is concealed by the cartilaginous pro- 

 longation of the ventral turbinate. There are two parietal cartilages on either 

 side, united by fibrous tissue. The dorsal cartilages are thin laminae which curve 

 ventro-laterally from the dorsal margin of the septal cartilage; they are prolonga- 

 tions of the nasal bones, and carry the alar cartilages on their anterior extremities. 

 The ventral pair are lateral continuations of the basal lamellae of the ventral tur- 

 binates. They lie along the nasal processes of the premaxillae; anteriorly they 

 become thicker, turn a little upward, and each blends with the cartilaginous pro- 

 longation of the upper coil of the ventral turbinate. The alar cartilages are of 



