230 INTERNAL FEMORAL REGION. 



Taking their fixed point from the tibia, they steady the femur upon 

 the leg, and the rectus, by being attached to the pelvis, serves to 

 balance the trunk upon the lower extremity. 



Internal femoral Region. 



Iliacus internus, 

 Psoas magnus, 

 Pectineus, 

 Adductor longus, 

 Adductor brevis, 

 Adductor magnus, 

 Gracilis. 



Dissection. These muscles are exposed by the removal of the 

 inner flap of integument recommended in the dissection of the 

 anterior femoral region. The iliacus and psoas arising from within 

 the abdomen can only be seen in their entire extent after the removal 

 of the viscera from that cavity. 



The Iliacus internus is a flat radiated muscle. It arises from the 

 inner concave surface of the ilium ; and, after joining with the 

 tendon of the psoas, is inserted into the trochanter minor of the 

 femur. 



Relations. By its anterior surface, within the pelvis, with the 

 external cutaneous nerve, and with the iliac fascia, which separates 

 the muscle from the' peritoneum, on the right from the cascum, and 

 on the left from the sigmoid flexure of the colon ; externally to the 

 pelvis with the fascia lata, rectus, and sartorius. By its posterior 

 surface with the iliac fossa, margin of the pelvis, and with the cap- 

 sule of the hip-joint, a synovial bursa of large size being interposed, 

 which is sometimes continuous with the synovial membrane of the 

 articulation. By its inner border with the psoas magnus and crural 

 nerve. 



The Psoas magnus (-^o'a, lumbus, a loin), situated by the side of 

 the vertebral column in the loins, is a long fusiform muscle. It 

 arises from the intervertebral substances, part of the bodies and bases 

 of the transverse processes, and from a series of tendinous arches, 

 thrown across the constricted portion of the last dorsal and four 

 upper lumbar vertebrae. These arches are intended to protect the 

 lumbar arteries and sympathetic filaments of nerves from pressure, 

 in their passage beneath the muscle. The tendon of the psoas 

 magnus unites with that of the iliacus, and the conjoined tendon is 

 inserted into the posterior part of the trochanter minor, a bursa being 

 interposed. 



Relations. By its anterior surface with the ligamentum arcuatum 

 internum of the diaphragm, the kidney, the psoas parvus, genito- 

 crural nerve, sympathetic nerve, its proper fascia, the peritoneum 

 and colon, and along its pelvic border with the common and external 

 iliac artery and vein. By its posterior surface with the lumbar ver- 

 tebrae, the lumbar arteries, quadratus lumborum, from which it is 



