What is "iliohypogastric nerve"

The iliohypogastric nerve is a nerve that originates from the lumbar plexus that supplies sensation to skin over the lateral gluteal region and motor to the internal and transverse abdominal muscles.

The nerve emerges from the psoas major in the outer part of its upper border, and crosses in front of the quadratus lumborum to the iliac crest, running behind the kidneys. Near the crest of the ilium the iliohypogastric nerve then pierces through the transversus abdominis, and divides between that muscle and the internal oblique muscle into a lateral and an anterior cutaneous branch.