346 



THE MUSCLES OF THE OX 



MANDIBIILAR MUSCLES 



The masseter is not so large as in the horse; a considerable part of it arises 

 on the facial tuberosity and is directed obliquely backward and downward, so that 

 it would draw the lower jaw forward as well as upward. 



The temporalis conforms to the temporal fossa, and is therefore longer and 

 entirely lateral in position. 



The pterygoideus medialis arises from the lateral surface of the perpendicular 

 part of the palatine bone and from the pterygoid process. Since the origin is nearer 



Fig. 302. — Muscles of Head of Ox; Ventral View. 

 d, d', Sterno-cephalicus; e, omo-hyoideus; 3, zygomaticus; /i, buccinator; i, depressor labiiinferioris; A-, orbicularis 

 oris; m, masseter; n, parotido-auricularis ; 0', zygomatico-auricularis; w, mylo-hyoideus ; 1, concha, convex surface; 

 B, anterior border of concha; 30^, angle of jaw; 3-9, facial vein; 44> parotid gland; 43, lower lip; 4S, angle of mouth; 

 50, 50\ mandibular gland; 69, larynx; X, wing of atlas. (After Ellenberger-Baum, Anat. fiir Kiinstler.) 



the median plane and the insertion further from it than in the horse, the muscle pro- 

 duces more marked lateral movement of the mandible. 



The pterygoideus lateralis is flattened transversely, wide and thin in front, 

 narrower and thicker behind. It has an extensive origin in the pterygo-palatine 

 fossa, where it is partly covered by the pterygoideus medialis. 



The occipito-mandibularis is absent. 



The digastricus has a tendinous origin on the paramastoid process of the 

 occipital bone; its bellies are short and thick. The intermediate tendon is round and 

 thick; it does not perforate the stylo-hyoideus. The anterior bellies are connected 

 beneath the root of the tongue by a layer of transverse muscle-fibers termed the 

 transversus mandibulse. 



