5® ANTHROPOLOGY. 



ribs, anterior to their angles ; its use is to assist the abdominal muscles in 

 expiration, and the diaphragm in inspiration. 



Splenius is long, fleshy, and tendinous, lying beneath the trapezius ; it is 

 divided about its centre into two portions : the inferior or splenius colli, and 

 the superior or splenius capitis. The former arises from the spines of the 

 third, fourth, fifth, and sixth dorsal, and is inserted into the transverse pro- 

 cesses of the three or four superior cervical vertebrae. The latter arises 

 from the spinous processes of the two superior and dorsal, and three inferior 

 cervical vertebrae, and is inserted into the back part of the mastoid process. 

 The use of the splenius muscles is to bend back the head ; and where one 

 only acts, to turn the head to that side. 



The next layer of muscles consists of the sacro-lumbalis, longissimus dorsi, 

 spinalis dorsi, cervicalis descendens, transversalis colli, trachelo-mastoideus, 

 and complexus. 



Sacro-lumbalis^ longissimus dorsi, and spinali'; dorsi are so closely con- 

 nected inferiorly as to appear but one mass ; they fill the hollow between 

 the angles of the ribs and the spinous processes; the first is external, the 

 second in the middle, and the third internal. They serve to strengthen the 

 spine, and to assist in respiration, 



Cervicalis descendens or ascendens arises internal to the sacro-lumbalis, 

 by four or five tendons, from as many of the superior ribs, between their 

 tubercles and angles; it is inserted into the posterior tubercles of the trans- 

 verse processes of the fourth, fifth, and sixth cervical vertebrae. Use: to 

 extend the neck, and incline or turn it to one side ; it may also assist in 

 respiration. 



Transversalis colli arises internal to the longissimus dorsi, by small slips, 

 from the transverse processes of five or six superior dorsal vertebrae ; it is 

 inserted by small tendons into the transverse processes of four or five inferior 

 cervical vertebrae ; its use is nearly similar to that of the last described muscle. 



Trachelo-mastoideus^ like a continuation of the longissimus dorsi, lies 

 internal to the last, and external to the next. It arises from the transverse 

 processes of three or four superior dorsal vertebrae, and from as many in- 

 ferior cervical ; ascending, it is inserted into the inner and back part of the 

 mastoid process, beneath the insertion of the splenius ; it assists in extend- 

 ing the neck, in bringing the head backwards, and inclining and rotating it 

 to one side. 



Complexus is thick and strong, and arises from the transverse and oblique 

 processes of three or four inferior cervical, and five or six superior dorsal 

 vertebrae, internal to the transversalis and trachelo-mastoideus ; it is inserted 

 close to its fellow into the occipital bone, between the two transverse ridges. 

 Use : to draw back the head ; to fix and support it on the spine ; also, to 

 rotate it as antagonistic to the splenius. 



Spinalis, or semi-spinalis colli, is one of the largest muscles in this region. 

 It arises from the extremity of the transverse processes of five or six supe- 

 rior dorsal vertebrae, and is inserted into the spmous processes of the second, 

 third, fourth, and fifth cervical vertebrae ; its use is to extend the neck, and 

 incline it to its own side. 

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