The ilioinguinal nerve also originates from the first lumbar nerve root.

The nerve travels around the flank and then anteriorly until it perforates the body wall near the anterior iliac crest. It initially lies between the transversus abdominis and the internal oblique muscles with the iliohypogastric nerve, before passing between the internal and external oblique muscles on the way to the superficial inguinal ring.

Question: What does the ilioinguinal nerve supply?

Answer: It supplies the superomedial thigh, the root of the penis and the upper part of the scrotum or mons pubis and labium majus.