Lumbar plexus
The lumbar plexus is formed from the anterior rami of L1 to L4 with contributions from the subcostal nerve (T12).
Diagrams illustrating the lumbar plexus
| Nerve | Origin | Structures supplied (motor) | Cutaneous supply |
|---|---|---|---|
| Iliohypogastric | T12-L1 | Internal oblique Transversus abdominis | Anterior cutaneous ramus Lateral cutaneous ramus |
| Ilioinguinal | L1 | Internal oblique Transversus abdominis | Anterior scrotal nerves in males Anterior labial nerves in females |
| Genitofemoral | L1-L2 | Cremaster | Femoral ramus Genital ramus |
| Lateral femoral cutaneous | L2-L3 | No motor function | Lateral femoral cutaneous |
| Obturator | L2-L4 | Obturator externus Adductor longus Adductor brevis Gracilis Pectineus Adductor magnus | Cutaneous ramus |
| Femoral | L2-L4 | Iliopsoas Pectineus Sartorius Quadriceps femoris | Anterior cutaneous branches Saphenous |
| Short Direct Branches | T12-L4 | Psoas major Quadratus lumborum |
Diagrams illustrating the lumbar plexus
 | |
 | |
 | |
 | |
Note the scrotum and penis cutaneous innervation is derived from branches of the ilioinguinal nerve, genital branch of genitofemoral nerve, scrotal branches of perineal nerve and perineal branches of posterior cutaneous nerve of thigh