Femoral Nerve

Description

Arising from the lumbar plexus (L2 to L4), the femoral nerve descends along the posterolateral border of psoas major and passes deep to the inguinal ligament to enter the femoral triangle, where it lies lateral to the femoral artery and vein. In the proximal thigh it divides into anterior cutaneous branches and muscular branches to iliacus, sartorius, and quadriceps femoris, while its long sensory continuation, the saphenous nerve, tracks distally with the femoral vessels through the adductor canal toward the medial knee and leg. Surrounding bony landmarks include the os coxae and proximal femur, with the tibia, fibula, and knee joint shown inferiorly to orient distal neurovascular relationships. Clean anatomy. This superior course through the pelvis and under the inguinal ligament matters because femoral neuropathy is often iatrogenic or compressive at exactly this level, after pelvic surgery, retroperitoneal hematoma, or prolonged lithotomy positioning. Loss of quadriceps strength with reduced patellar reflex and sensory change over the anterior thigh and medial leg map tightly to the femoral nerve and saphenous territory, and this view helps separate that pattern from a sciatic distribution. For regional anesthesia, the depiction supports safe planning of a femoral nerve block by keeping the nerve’s lateral relationship to the femoral artery in mind, and by reinforcing how close the nerve sits to the iliopsoas compartment proximally. Use this illustration for teaching lumbar plexus derivatives in gross anatomy, neuroanatomy, and anesthesiology curricula, or for surgical and pain medicine texts covering femoral triangle approaches, catheter placement, and postoperative neuropathy documentation. It also suits patient-facing education on quadriceps weakness and anterior thigh numbness after pelvic or hip procedures. Anatomical accuracy verified by SciePro's Medical Advisory Board.