ILIO-PSOAS 



99 



passage of a large artery and vein the aorta and vena cava, and 

 the esophagus. 



With the muscles thus far described the walls of the cavities of 

 the trunk dorsal and ventral are completed (see page 52). 



INTERIOR ABDOMINAL MUSCLES 



The psoas major and iliacus. These are two muscles within 

 the abdomen (on the posterior wall) which pass out over the 

 brim of the pelvis into the thigh. 



Psoas major. Origin. The sides of the lumbar vertebrae. 

 Insertion. Trochanter minor of the femur. 



4 



13 



10 



FIG. 83. ABDOMINAL MUSCLES, INTERIOR. 



1-5, Psoas minor and major; 6, attachment of psoas major to trochanter minor; 

 7, 7, 8, 8, iliacus; 9, 9, cut tendon rectus femoris; 10, 10, obturator externus; 11-13, 

 quadratus lumborum; 14, 14, transversus. (Sappey.} 



Iliacus. Origin. The iliac fossa. Insertion. With the psoas 

 on the trochanter minor of the femur. 



Action. They act together as one muscle, the ilio-psoas, to 

 flex the thigh, at the same time rotating it, so that the foot turns 

 outward. 



