Action.—An extensor of the thigh.
M. adductor longus ([Fig. 91], g; [Fig. 92], f).—A thin muscle which covers the dorsal half of the medial surface of the adductor femoris ([Fig. 92], g).
Origin by muscle-fibres from the median three-fourths of the cranial border of the pubis, the line of origin forming a medial continuation of that of the pectineus ([Fig. 92], e).
Insertion by a thin aponeurosis into the external linea aspera of the femur along the second and third fifths of the bone.
Relations.—With its medial or cranial surface the adductor longus forms part of the boundary of a depression among the muscles at the proximal end of the medial side of the leg. This depression is called the iliopectineal fossa; it contains the femoral vein and artery and saphenous nerve imbedded in fat ([Fig. 127]). The medial edge of the adductor longus is in relation with the integument; the lateral edge with the pectineus ([Fig. 92], e). Inner or caudal surface with the adductor femoris ([Fig. 92], g).
Action.—Adductor of the thigh.
[Fig. 92].—Second Layer of Muscles on the Medial Side of the Thigh.
![[Fig. 92]](#3418956513767812439_illo200lg.jpg.id-6158922993820639974.wrap-0.html.html){kind=link}
a, M. tensor fasciæ latæ; a′, fascia lata; b, M. rectus femoris; c, M. vastus medialis; d, M. iliopsoas (cut); e, M. pectineus; f, M. adductor longus; g, M. adductor femoris; h, h′, M. semimembranosus; i, M. semitendinosus (i′, its tendon); j, medial head of M. gastrocnemius; k, M. popliteus; l, M. flexor longus digitorum. 1, patellar ligament; 2, ligamentum collaterale tibiale.
M. pectineus ([Fig. 92], e).—A flat band of fibres closely united with the adductor longus (f), of which it appears to be a lateral continuation.