460 



RESPIRATORY SYSTEM OF THE OX 



epiglottis, the angle of the union of the thyroid laminae, and the crico-thyroid 

 membrane. The hyo-eijiglotticus muscle is large and bifid. 



THE TRACHEA 



The caliber of the trachea is relatively small, its width being about an inch 

 antl a half (ca. 4 cm.) and its height one and a half to two inches (ca. 4 to 5 cm.). 

 The rings are smaller, and number aljout fifty. In the neck their free ends are sep- 



Frontal eviincncc 



Great ethmo-turbinal 



Superior turhinal 



Superior meatus 

 Middle meatus 



Inferior 

 turhinal 



Naso- 

 labial 

 glands 



Body of 

 mandible 



(rento- 

 glossus 



Mylo-Jty 

 oidcus 



Genio- 

 hyoideus 



Thyroid cartilage 



Fig. 365. — Sagittal Section of Head of Cow. 

 1, Cerebral hemisjjhere; 2, lateral ventricle; 3, thalamus; 4, corpora quadiigemina; 



5, optic chiasma; 



6, pituitary body; 7, pons; S, medulla oblongata; 9, cerebellum; 10, spinal cord; 11, ventral straight muscles; 

 12, pharyngeal lymph gland; 13, arytenoid cartilage; H, eijiglottis; 15, cricoid cartilage; 16, vocal cord; 17 , 

 palatine sinus; 18, soft palate; 19, Eustachian oi)ening; C\, ('2, ('3, first, second, and third cervical vertebrae; B.o., 

 basioccipital; Sp., presphenoid. 



arated by a varying interval, so that the tube is flattened and membranous dor- 

 sally. In the thorax the ends are in apposition, so that they form a ridge dorsally. 

 The trachea is adherent to the right limg from the second rib backward. The 

 bifurcation is opposite the fourth intercostal space. 



THE BRONCHI 

 There are three chief bronchi. The bronchus for the apical and the anterior 

 cardiac lobe of the right lung is detached from the trachea at a considerable dis- 

 tance anterior to the bifurcation. 



