318 



THE MUSCLES OF THE TRUNK. 



INTERSPIXALES AND INTERTRANSVERSALES. The interspiuales are short 

 vertical fasciculi of fleshy fibres, placed in pairs between the spinous processes of 

 contiguous vertebrae. In the neck, from the axis downwards, they are roundish 

 bundles attached to the two parts into which the spinous processes are divided. In 

 the dorsal region they are for the most part absent^ a few fibres only being present 

 in one or two of the highest and lowest spaces. In the loins they are flattened 

 bands, one on each side of the interspinous ligament, and extending the whole 

 length of the spinous processes. 



Variety. Longer interspinous bundles are sometimes found in the neck passing- over one 

 or two vertebras, and forming- a transition to the spinalis cervicis muscle already described. 



Fig. 286. DEEP POSTERIOR MUSCLES OF THE UPPER 



PART OP THE VERTEBRAL COLUMN. (Allen Thom- 



son. ) 5- 



a, external occipital protuberance ; 5, surface between 

 the superior and inferior curved lines into which the 

 complexus is inserted ; c, spine of axis ; d, transverse 

 process of atlas ; c, transverse process of first dorsal 

 vertebra ; f, lamina of sixth dorsal vertebra ; 1, rectus 

 capitis posticus minor muscle ; 2, rectus posticus major ; 

 3, obliquus superior ; 4, obliquus inferior ; 5, rectus capitis 

 lateralis ; 6, 6, trachelo-mastoid, the muscle of the right 

 side turned inwards and its slips of origin from the dorsal 

 and cervical vertebrae separated from each other ; 7, 7, 

 transversalis cervicis, the figures are placed near the 

 extreme ends of the muscle on the right side ; 7', on the 

 left side, longissimus dorsi ; 8, 8, cervicalis ascendens, 

 the muscle of the right side is spread out ; 8', 8', on 

 the left side, tendinous insertions of the ilio-costalis and 

 accessorius muscles ; 9, upper part of the semispinalis 

 colli of the left side ; 10, placed on the seventh rib of 

 the right side close to the insertion of its levator cost 

 muscle ; 11, 11, three rotatores dorsi. 



The intertransversales are short mus- 

 cles passing nearly vertically from vertebra to 

 vertebra between the transverse processes. 

 In the cervical region there are two rounded 

 fleshy bundles below each transverse pro- 

 cess, the one descending from the anterior, 

 the other from the posterior part of the pro- 

 cess. In the dorsal region there are small 

 fleshy bundles in the lowest three or four 

 spaces ; in the middle spaces they are replaced 

 by small tendinous bands which constitute 

 the so-called intertransverse ligaments ; and 

 in the upper spaces they are usually altogether 



wanting. In the lumbar region there are again two sets : one set, the intertrans- 

 versales laterales, lie between the transverse processes ; the other set, intertrans- 

 versales mediales or interaccessorii, pass from the accessory process of one vertebra to 

 the mamillary process of the next. 



The posterior intertransversales of the neck and the mesial intertransversales of the loins 

 are in series with the rudimentary thoracic muscles, and belong to the dorsal musculature. 

 The anterior cervical muscles with the scaleni, and the lateral lumbar muscles with the 

 quadratus lumborum correspond to the levatores costarum and intercostal muscles of the 

 thoracic region. 



SHORT POSTERIOR CRANIO-VERTEBRAL OR SUBOCCIPITAL MUSCLES. The rectus 



