326 



Muscles of the Lee 



Costa xn 



M. quadratus 

 lumborum 



M. psoas minor 



M. psoas major 



Costa XII 



Corpus vertebrae 

 liimbalis I 



M. transversus 

 abdominis 



Crus mediale 

 diaphragmatis 



M. quadratus 

 lumborum 



Origins of the 

 m. psoas major 



bpina 



iliaea . -_^ 



anterior '^ 



superior 



Li game n- 

 tuni ilio- 

 lumbale 



Pro- 

 montoriun 



M. psoas majo] 



(cut off and 



reflected) 



JI. iliacus 



Femur 



371. Lumbar muscles, 



\'icwed from in front. (The largest part of the 

 left 111. psoas major has been removed.) 



M. (nuulratus liiniburiuu (see also Figs. 314, 315 ami 333). Form: flat, oblong- 

 "piadrangular. Position: posterior wall of the peritoneal cavity, directly in front of the anterior 

 layer of the fascia lumbodorsalis, covered partly in front hy the m. psoas major. Two, often slightly 

 separated, layers. Ante7io?- layer. Origin: procc. transversi of the S*!" 2Dd lumbar vertebra. 

 Insertion: inferior border of the 12tlM-ib and the liody of tlie 1 2 '^ thoracic vertebra. Posterior 

 layer. Origin: labium internum cristae iliacae and lig. iliolumbale. Insertion: inferior margin 

 of 12t'i rib and procc. transversi of the 4th jst lumbar vertebra. Action: it draws the last rib 

 downward ; it bends the lumbar spine lat^^-alward. T n n (> r v a t i o n : rami musculares ])lexus lumbalis. 



M, iliopsoas cdiisists of in. psoas minor, m. psoas inajor and nt. iliacus. 



31. psoas minor (see also Figs. 314, 315 and 333), variable. Form: flat, long, narrow. 

 Position: directly in front of the m. psoas major. Origin: lateral surface of the bodies of the 

 12th thoracic and 1st lumbar vertebra. Insertion: fascia iliaea. Action: it bends the lumbar 

 spine lateralward and makes the fascia iliaea tense. Innervation: rami musculares plexus lumbalis. 



