MUSCULAR SYSTEM OF THE RED HOWLING MONKEY 



33 



Superficial Oblique System 



It is represented by a single muscle, the splenius. 



M. splenius: This strong muscle originates from the ligamentum 

 nuchae, between the spine of the axis and that of thoracic vertebra 1 . 

 Some of its fibers are often displaced laterally and arise directly from 

 the nuchal fascia. The flattened and fleshy belly is trapezoid-shaped. 

 Its short parallel side limits, with that of the muscle from the opposite 

 side, a small triangular space over the occipital and suboccipital 

 regions. Insertion takes place on the outer half of the superior nuchal 

 line deep to the endings of m. rhomboideus and trapezius (fig. 5). 

 There was no splenius cervicis. 



Sirena (1871) includes the first two or three thoracic vertebrae in 

 the origin of the muscle and, more interesting, describes the fibers along 

 its lateral margin as being tendinous and inserted on the transverse 

 process of the atlas. HiU (1962) also mentions such a vertebral ending. 



tD 



Figure 11. — Section at the level of L4 showing arrangement of thoracolumbar fascia 

 (1, anapophysis; 2, metapophysis; 3, m. spinalis; 4, m. longissimus; 5, aponeurosis sacro- 

 spinalis and its septum or attached sheet; 6, thoracolumbar fascia; 7, m. iliocostalis; 8, 

 m. obliquus externus abdominis; 9, m. obliquus internus abdominis; 10, m. transversus 

 abdominis). 



