Editing Retroperitoneum (section)

=== Somatic nervous system ===
* See Table in Male Pelvis Anatomy Chapter Notes
* The somatic sensory and motor nerves of the lower abdomen and lower extremities originate in the retroperitoneum. They form the '''lumbosacral plexus''' from the anterior rami of the lumbar and sacral nerves along with T12
* The subcostal nerve (T12) runs inferior to the 12th rib.
* '''The''' '''sciatic nerve''' receives input from L4-S3 and provides the bulk of motor and sensory input to the lower extremities, including motor innervation to the posterior thigh compartment and all muscles in the leg and foot.
** '''Injury to this nerve may occur secondary to prolonged hip hyperflexion used during a high lithotomy position for vaginal and urethral procedures'''.