370 



THE MUSCLES OF THE DOG 



MUSCLES OF THE MANDIBLE 

 The masseter is thick and its superficial face is strongly convex. It arises 

 from the zygomatic arch, and extends beyond the branch of the jaw below and be- 

 hind. Three partly separate strata may be recognized in its structure. 



The temporalis is very large and 

 strong, and contains much tendinous 

 tissue. It arises from the temporal 

 fossa and the orbital ligament and 

 ends on the coronoid process of the 

 mandible. It blends in part with 

 the masseter. 



The pterygoideus lateralis is 

 not distinct from the medialis. 

 The digastricus is absent. 

 , The occipito-mandibularis is a 



strong, round, fleshy muscle, which 

 arises on the paramastoid process 

 and is inserted into the border and 

 medial surface of the ramus of the 

 mandible at the level of the last 

 molar teeth; it sometimes has a 

 tendinous intersection. 



HYOID MUSCLES 



The mylo-hyoideus is well de- 

 veloped. 



The stylo-hyoideus is very slen- 

 der, and is inserted into the body of 

 the hyoid bone. 



The hyoideus transversus and 

 omo-hyoideus are absent. 



The stemo-thyro-hyoideus is 

 large and arises chiefly on the first 

 costal cartilage. It is clearly di- 

 vided into stemo-thyroideus and 

 stemo-hyoideus . 



Fig. 321. 



-Yextral Muscles of Head, Neck, 

 OF Dog. 



N'D Thorax 



a, Mylo-hyoideus; b, occipito-mandibularis; c, sterno- 

 hyoideus; c', sterno-thyroideus ; d, sterno-cephalicus; e, brachio- 

 cephalicus; /, subscapularis; ff, superficial pectoral; h, deep pec- 

 toral; i, rectus abdominis; k, obliquus abdominis externus; Z, 

 long head of triceps; m, medial head of triceps; n, biceps 

 brachii; o, brachialis; 1, 1' , 1" , mandibuLir lymph glands; 2, 

 thyroid gland; 3, external jugular vein. (Ellenberger-Baum, 

 Anat. d. Himdes.), 



MUSCLES OF THE THORACIC LiMB 



The trapezius is thin, and is 

 divided into cervical and thoracic 

 portions by a narrow aponeurotic 

 part. Its line of origin extends from 

 about the middle of the dorsal bor- 

 der of the neck to the ninth or tenth thoracic spine, the right and left muscles 

 meeting (except at their posterior part) on a median fibrous raph6. It is inserted 

 into the entire length of the spine of the scapula. 



The omo-transversarius arises by a tendon on the lower part of the spine of 

 the scapula (where it is often partially blended with the trapezius), and is inserted 

 into the wing of the atlas. 



