Lumbar plexus (English)

The lumbar plexus is formed by the anterior rami of spinal nerves L1–L4. Six terminal branches arise from the plexus: the iliohypogastric nerve, ilioinguinal nerve, genitofemoral nerve, obturator nerve, lateral femoral cutaneous nerve and femoral nerve. Occasionally an accessory obturator nerve can be present. The iliohypogastric and ilioinguinal nerves arise from spinal nerve L1; they supply motor innervation to the anterolateral abdominal wall and cutaneous innervation to the lower abdomen, inguinal and genital regions. The genitofemoral and obturator nerves arise from the anterior divisions of the anterior rami of spinal nerves L1-L2 and L2-L4, respectively; the genitofemoral nerve provides cutaneous innervation to the upper thigh and genital region, while the obturator nerve provides cutaneous and muscular innervation to the medial thigh (adductor compartment). The lateral femoral cutaneous and femoral nerves arise posterior divisions of anterior rami of spinal nerves L2-L3 and L2-L4 respectively; these supply cutaneous innervation to the thigh region (except for the posterior part) and medial aspect of the leg, while the femoral nerve also provides muscular innervation to the iliacus muscle and muscles of the anterior compartment of the thigh.