LATERAL CERVICAL MUSCLES 



275 



Nerve-supply. — Dorsal branch of the second cervical nerve. 



10. ObUquus capitis anterior (s. cranialis) .— This short, thick, quadrilateral 

 muscle lies on the side of the atlantooccipital articulation. 



Origin. — The anterior edge and ventral surface of the wing of the atlas. 



Insertion.~-The paramastoid process and nuchal crest of the occipital bone 

 and the mastoid process. 



Action. — Acting together, to extend the head on the atlas; acting singly, to 

 flex the head laterally. 



Structure. — The muscle contains a good deal of tendinous tissue. The direction 

 of its fibers is forward, upward, and inward. 



Fig. 269. — Deepest Layer of Muscles of Neck of Horse. 

 a, Obliquus capitis anterior; 6, obliquus capitis posterior; c, rectus capitis lateralis; d, rectus capitis ventralis 

 minor; e, rectus capitis ventralis major; /, longus colli; g, g', scalenus; h, longissimus costarum; t, longissimus dorsi; 

 fc, spinalis et semispinalis; ?, multifidus dorsi; m, multifidus cervicis; h, intertransversales; o, o', rectus capitis dorsalis 

 major; p, rectus capitis dorsalis minor; q, tendon of insertion of complcxus; 1, lamellar part, 1', funicular part of liga- 

 mentum nucha ; ^, nuchal crest; 3, paramastoid process; 4< edge of wing of atlas; 5, transverse, and 6, articular, 

 processes of cervical vertebrse; 7, nerves of brachial plexus (cut) ; 8, first rib. (EIlenberger-Baum, Anat. d. Haustiere.) 



Relations. — Superficially, the complexus, the aponeurosis of the splenius, longus 

 capitis, and brachiocephalicus, overlying which are the posterior auricular muscles, 

 artery, and nerve, and the parotid gland; deeply, the dorsal straight muscles, 

 the occipito-hyoideus, the atlanto-occipital articulation, the posterior meningeal 

 artery, and a branch of the occipital nerve. 



Blood-supply. — Occipital artery. 



Nerve-supply. — Dorsal branch of the first cervical nerve. 



11. Rectus capitis dorsalis major. — This muscle extends from the axis to the 

 occipital bone, in contact with the ligamentum nuchse. 



Origin. — The edge of the spinous process of the axis. 



