The femoral nerve arises from the anterior rami of nerves L2 to L4 (Fig. 4.173). It descends through the substance of the psoas major muscle, emerging from the lower lateral border of the psoas major (Fig. 4.174). Continuing its descent, the femoral nerve lies between the lateral border of the psoas major and the anterior surface of the iliacus muscle. It is deep to the iliacus fascia and lateral to the femoral artery as it passes posterior to the inguinal ligament and enters the anterior compartment of the thigh. Upon entering the thigh, it immediately divides into multiple branches.