MUSCLES OF THE NECK VENTRAL GROUP LATERAL GROUP 347 



HYOID MUSCXES 



The mylo-hyoideus is thicker and more extensive than in the horse. 



The stylo-hyoideus has a long, slender tendon of origin which is attached to the 

 muscular angle of the great cornu of the hyoid bone. The insertion is fleshy and 

 is not perforated by the digastricus. 



The genio-hyoideus is much more developed than in the horse. 



The kerato-hyoideus has an additional attachment on the middle cornu of the 

 hyoid bone. 



The hyoideus transversus is bifid. 



The stemo-thyro-hyoideus has no intermediate tendon and is thicker. 



The omo-hyoideus arises as a thin band from the fascia over the third and 

 fourth cervical vertebra. It blends here with the rectus capitis ventralis major. 



The occipito-hyoideus is thick. Its large lateral part entirely covers the para- 

 mastoid process (from which it arises) and is inserted into the muscular angle of 

 the great cornu. The smaller medial part arises from the ventral end of the para- 

 mastoid process and ends on the medial face of the great cornu below the dorsal 

 end. 



Muscles of the Neck 

 a. ventral group 



The cervical cutaneus is absent. 



The stemo-cephalicus consists of two muscles. They arise from the manu- 

 brium sterni and first rib. The superficial muscle is the stemo-mandibularis ; it 

 is inserted on the anterior border of the masseter, the ramus of the mandible, and 

 the buccal fascia. The deep muscle is the stemo-m.astoideus ; it crosses under the 

 preceding and ends on the mastoid processes, the mandible, and, in common with 

 the rectus capitis ventralis major, on the basilar part of the occipital bone. 



There are two scaleni. The scalenus ventralis (s. primse costse) arises from 

 the transverse processes of the third to the seventh cervical vertebrae and ends on 

 the first rib. It is traversed by the roots of the brachial plexus, which divide it 

 into bundles. The emerging brachial artery separates a narrow part below from 

 the main mass. The scalenus dorsalis (s. supracostalis) arises usually on the 

 transverse processes of the fourth, fifth, and sixth cervical vertebrae. Its wide 

 posterior part lies on the ventral part of the serratus thoracis; it is attached to the 

 third rib and to the serratus thoracis. 



The rectus capitis ventralis major arises on the third to the sixth cervical 

 transverse processes, and blends at its insertion with the sterno-mastoideus and 

 the cleido-mastoideus. 



The rectus capitis ventralis minor is larger than in the horse. 



The rectus capitis lateralis and longus colli resemble those of the horse. 



The intertransversales are large. From the sixth cervical vertebra forward 

 they form a muscular mass (M. intertransversarius longus) which is inserted into 

 the wing of the atlas. 



B. LATERAL GROUP 



The splenius is thin. It arises directly from the first three or four thoracic 

 spines, and ends by a thin tendon on the occipital bone, the wing of the atlas, 

 and the transverse process of the axis, blending with the brachiocephalicus, longis- 

 simus capitis, and omo-transversarius. The remaining muscles present no very 

 marked differential features. 



