234 



FASCIA AND MUSCLES OF THE HORSE 



Blood-supply. — Occipital artery. 



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



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

 muscle of the head). — 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 nuchse. 



Action. — To extend the head. 



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



Fir,. ISO. — Deepest Layer of Muscles of Neck of Horse. 

 a, Obliquus capiti.s anterior; b, obliquus capitis posterior; c, rectus capitis lateralis; d, rectus capitis anterior 

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

 dorsi; k, spinalis et semispinalis; /, 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 i>art of ligamentum nuchus ^, occipital crest; S, paramastoid process; 4. edge of wing of atlas; 5, 

 transverse, and 6, articular, processes of cervical vertebras 7, nerves of brachial plexus (cut); 8, first rib. 

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



superficial and d(>ep. 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 jiosterior minor. The dorsal branch of the first cervical 

 nerve appears between this muscle and the small ol)lique. 



Blood-supply. — Occipital artery. 



Nerve-supply. — Dorsal branch 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. 



