482 



DIGESTIVE SYSTEM OF THE PIG 



The parotid gland is large and distinctly triangular. It extends very little on 

 to the masseter muscle, and its upper angle does not quite reach the base of the ear. 

 It is pale in color, and is embedded in fat in animals in good condition. On its deep 

 face are several large subparotid lymph glands, some of which are only partially 

 covered by the parotid. The parotid duct arises on the deep face, has a course 

 similar to that of the ox, and perforates the cheek opposite the fourth or fifth upper 

 cheek tooth. Small accessory parotid glands (Glandulee parotidese accessorise) may 

 be found along the course of the duct. 



The mandibular or submaxillary gland is small, reddish in color, and oval in 

 outline; it is covered by the parotid. Its superficial face is convex, and is marked by 

 rounded prominences. From its deep face a narrow process extends forward about 

 two or three inches (ca. 5 to 7.5 cm.) beneath the mylo-hyoideus muscle along with 

 the duct. The latter opens near the frenum linguae, but there is no papilla. 



The sublingual gland has an arrangement similar to that of the ox. The pos- 

 terior part (Glandula sublingualis grandicanalaris) is reddish-yellow in color, and 

 is about two inches (ca. 5 cm.) long and half an inch wide; its posterior end is in 

 relation to the mandibular gland and its duct. The anterior part (Gl. sublingu- 

 alis parvicanalaris) is much larger, being two or three inches (ca. 5 to 7 cm.) long 

 and about twice the width and thickness of the posterior part. All or most of the 

 ducts from the posterior part unite to form the ductus sublingualis major, which 

 opens near the ductus mandibularis. Eight or ten ductus sublinguales minores 

 convey the secretion from the anterior part through the floor of the mouth. 



Fig. 417. — S.iGiTTAL Section of Pharyngeal Region of Pig, Partly Schematic. 

 1, Palatine bone; 2, sphenoid bone; 2' , sphenoidal sinus; 2" , occipital bone; 3, epiglottis; -4, arytenoid cartilage; 

 5, thyroid cartilage; 6', root of tongue; 7, mouth cavity; 8, isthmus faucium; 9, hard palate; 10, septum nasi; 11, 

 ventral muscles of head; a, soft palate; a', free edge of a; b, dorsal wall of pharynx; c, fornix of pharynx; d, cavity of 

 larynx; e, (7, naso-pharynx; /, oro-pharynx; /(, posterior pillar of soft palate; (, dotted line indicating lateral boundary 

 between nasal cavity and pharynx; ^-j aditus laryngis; /, aditus cesophagi; m, Eustachian orifice; n, pharyngeal recess; 

 o, posterior naris. (After Ellenberger, in Leisering's Atlas.) 



THE PHARYNX 



The pharynx presents in its posterior part a median cul-de-sac about an inch 

 and a half (ca. 3 to 4 cm.) long, which is situated between the ventral straight 

 muscles of the head and the origin of the oesophagus; this is termed the diverticu- 

 lum pharyngeum. Its ventral margin is formed by the junction of the posterior 

 pillars of the soft palate, which contain muscular tissue derived from the palatinus 

 and palato-pharyngeus. The fornix of the pharynx is divided by a median fold of 

 mucous membrane which is a direct continuation of the septum nasi. On either 

 side of this is an infundibulum in which the Eustachian tube opens. 



