Which plexus gives rise to the femoral nerve?

• A. Cervical plexus
• B. Brachial plexus
• C. Sacral plexus
• D. Lumbar plexus

Answer: (D)

The femoral nerve comes from the lumbar plexus. This plexus is formed by the ventral rami of L1–L4 (with occasional small contribution from T12), and the femoral nerve specifically emerges from the posterior divisions of L2–L4 within that plexus. It then travels under the inguinal ligament into the anterior thigh, innervating the main extensors there (iliopsoas, quadriceps, sartorius, pectineus) and providing sensory supply to the anterior thigh and the medial leg via the saphenous branch. The other plexuses govern different regions: the cervical plexus serves neck and some head/diaphragm functions; the brachial plexus serves the upper limb; the sacral plexus handles much of the lower limb but mainly the posterior thigh and the leg, including the sciatic nerve.