ABSTRACT
The ilioinguinal nerve originates from the L1 nerve root (rarely L2) and descends along the quadratus lumborum and the iliacus muscles. Piercing the transversus abdominis muscle and the internal oblique muscle, the nerve comes to run under the external oblique muscle. As it runs between the internal and external oblique muscles distal and medial to the anterior superior iliac spine, the nerve changes direction and either accompanies the spermatic cord in men or the round ligament in women, the ligamentum teres of the uterus (Figure 33.1). Sensory fibers branch off to innervate the skin of the scrotum in men or the skin of the labia major in women. An additional sensory branch supplies the skin over the inguinal ligament.
