1 1 i ! IF TH1 



THE LONG MUSCLES OF THE BACK. 



M9 



musi les of the bai k (Figs, 

 the direction of their i ili. In th< superficial the5^j 



to the trai to the ribs; in tl 



inalis, they j I om the transver 1.. 



ing to the upper la the only muscle ] 



The First Layer. The Spinotransversalis and Spinalis. 



The n of this fill the 



the vertebrae and the angles of the ribs, and extend :nn, 



usually the entire length of the bai k. With the 

 beneath the skin, between the trape; rid the lath 



pletel) 1 either by the flat n r by tl. he lum 



Thi m a sii mplicated mu 



The sac rospin alis . and : . 



which extend- from th( rum and the ( f the iliun-. 



a single n ily in il tion, dividi 



muscles, the external and weaker iliocostalis and the intei 



Internal to the latter muscle and adherent to it is situated th< \ 



layer of the long mi f the back is arra in three I 



the vertebral column, a \ median one, the Ion us, an ext 



an internal one the spinal: . m th< 



mass, wh tic and which ai 



rum, from the spinou imbarverl 



included between th f the lumbar f; 



and the longissimus dorsi pass upward directly from this ma 



The Uiocostalis I istheouti 



of three subdivis the iliocostal is lumborut 



Tl. ^umU*ru))'i 1 id 24] mmon with tl 



inserts into the angles of the fifth to the twelfth ribs. 1 



: tendons, while the lower insertions are in thi 

 which is the and pa the lower border oi the twelfth ri 



The greater portion oi the origin oi thi . ... 



the iliocostalis lumborum. It arises by me; 



of the angles of the twelfth to the seventh ribs, and is ins svhich • the 



angles oi the sixth to the first ribs and to the trai ssof the 1 



The iliocostal is ccr: .. rid 241 . 



slender muscle the origin of which is intiir. with the ili stalis It coi 



from the upper and middle ribs in a variable manner an by narrow tendons into the 



transverse processes oi the middle cervical vertebrae immediately alongside of the scalenus pos- 

 terior .see page 175), with the origin of which it may be adherent. 



