THE LARYNX 



467 



the two parietal cartilages, which curve laterally and toward each other. A 

 grooved plate extends outward from the septal cartilage in the floor of the nostril, 

 and another lamina supports the alar fold of the inferior turbinal bone. 



The length of the nasal cavity varies greatly in different breeds, correspond- 

 ing, of course, to the length of the face. The cavity is roomy, but is very 

 largely occupied by the turbinals and the lateral masses 

 of the ethmoid bone. The middle meatus is short and 

 narrow, and divides posteriorly into two branches; the 

 upper branch leads to the ethmoidal meatuses; the 

 lower branch joins the inferior meatus. The inferior 

 meatus is very small in its middle part, owing to the 

 great develojinKnit here of the inferior turbinal. The 

 posterior part of the nasal cavity is divided by a hori- 

 zontal plate, the lamina transversalis, into an upper 

 olfactory part and a lower respiratory part. The 

 sinuses have been described (vide Osteology). 



Fi 



372. — Nasal Cartilages of 

 Dog. 



a, Ui)per parietal cartilasp; 

 6, lower parietal cartilage; c, alar 

 cartilage. (After Ellenberger, in 

 Lei.sering's Atlas.) 



The laminae of the thyroid 



THE LARYNX 



The larynx is relatively short. The lamina of the 

 cricoid cartilage is wide; the arch is grooved laterally. 

 cartilage are high, but short; they unite ventrally to form the body, on which there 

 is anteriorly a marked prominence, and posteriorly a deep notch. The oblique line 

 on the outer surface of the lamina is prominent. There is a rounded notch (Fissura 

 thyreoidea) below the short anterior cornua for the passage of the superior laryngeal 

 nerve. The j^osterior cornu is strong, and has a rounded surface for articulation with 



Fig. 373. — Sagittal Section of Nas.^l Region of Dog. 

 ^,Skin; ;?, parietal cartilage; 3, floor of nasal cavity; 4. lamina transversalis; 5, mucous membrane of hard 

 palate; 6,upperlip; 7, frontal bone; S, frontal sinus; 9, cranial plate of frontal bone; /O, cranial cavity; //.dotted 

 line indicating anterior limit of olfactory region; o, superior turbinal; 6, inferior turbinal; b', b", inferior turbinal 

 fold; c, e, ethmoturbinals; d, cribriform plate of ethmoid; /, superior meatus; y, middle meatus; h, inferior 

 meatus; i, naso-pharyngeal meatus. (After Ellenberger, in Leisering's Atlas.) 



the cricoid cartilage. The arytenoid cartilages are relatively small, and have between 

 them a small interarytenoid cartilage. The epiglottis is quadrilateral ; its lower part 

 or stalk is narrow, fitting into the angle of the thyroid cartilage. The cuneiform 

 cartilages are large and somewhat crescent-shaped; they are not blended with the 

 epiglottis. 



The false vocal cords extend from the cuneiform cartilages to the th>Toid. 



