The iliohypogastric nerve is a branch of the anterior division of the first lumbar nerve and may also receive a branch from the twelfth thoracic nerve. It passes through the upper part of the lateral border of the psoas major muscle. It then runs in the extraperitoneal fat obliquely downward and laterally across the front of the quadratus lumborum muscle behind the kidney to the crest of the ilium, where it pierces the transversus abdominis muscle. It runs forward along the crest of the ilium, between the transversus abdominis and internal oblique muscles. It then divides into a lateral cutaneous and a anterior cutaneous branch about six centimeters behind the anterior superior spine of the ilium. The lateral cutaneous branch passes through the internal and external oblique muscles above the crest of the ilium, and supplies the skin of the gluteal region behind the area of distribution of the lateral cutaneous branch of the last thoracic nerve. The anterior cutaneous branch passes forward along the crest of the ilium, pierces the internal oblique muscle at the level of the anterior superior spine of the ilium, and passes through the aponeurosis of the external oblique muscle about two and a half centimeters above the external superficial inguinal ring. It sends muscular branches to the rectus abdominis and pyramidalis muscles, and cutaneous branches to the skin over the hypogastrium. The iliohypogastric nerve and its branches supply the external oblique, internal oblique, transversus abdominis, rectus abdominis, and pyramidalis muscles, and the skin of the posterolateral gluteal region and above the pubis.

Nervus iliohypogastricus

Nervus iliopubicus

Nerf ilio-hypogastrique