234 



FASCIiE AND MUSCLES OF THE HORSE 



Blood-supply. — Ofcijiital artery. 



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



11. Rectus capitis posterior major (s. dorsalis major) (great posterior straight 

 muscle of the lieadj. — 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. 



Insertion. — The occipital bone, below and external to the complexus and 

 ligamentum nucha. 



Action. — To extend the head. 



Structure. — The muscle is fleshy and may be divided into two parallel portions, 



Fig. 180. — Deepest Layer of Muscles of Neck of Horse. 

 a, Obliquus capitis anterior; 6, obliquus capitis posterior; c, rectus capitis lateralis; d, rectus cai)itis anterior 

 minor; e, rectus capitis anterior major; /, longus colli; g, g', scalenus; h, transversalis costarum; i, longissimus 

 dorsi; k, sjjinalis et semispiiialis; /, multifidus dorsi; m, multifidus cervicis; n, intertransversales; o, o', rectus 

 capitis posterior major; p, rectus capitis posterior minor; q, tendon of insertion of complexus; 1, lamellar part, 

 /'.funicular part of ligamentum nucha"; 2, occipital crest; d, paramastoid process; 4. edge of wing of atlas; 5, 

 transverse, and 6", articular, processes of cervical vertebra; 7, nerves of brachial plexus (cut); S, first rib. 

 (EUenberger-Baum, Anat. tl. Haustiere.) 



superficial and deei). The former blends somewhat with the terminal part of the 

 complexus. The deep portion may be termed the rectus capitis posterior medius. 



Relations. — Superficially, the anterior oblique, splenius, and complexus; 

 internally, the ligamentum nucha^; deeply, the atlas, the occipito-atlantal articula- 

 tion, and the rectus capitis posterior minor. The dorsal branch of the first cervical 

 nerve appears between this muscle and the small oblique. 



Blood-supply. — Occipital artery. 



Nerve-.'<iipply. — Dorsal ])raii('h of the first cervical nerve. 



12. Rectus capitis posterior minor (s. dorsalis minor) (small posterior straight 

 muscle of the head). — Tliis small muscle lies under cover of the preceding. 



