Plan of lumbar plexus. (Iliohypogastric visible at upper left.)
The lumbar plexus and its branches. (Iliohypogastric visible at upper left.)
|Innervates||Sensory: Skin over the lateral gluteal region and above the pubis
Motor: internal and transverse abdominal muscles
|Anatomical terms of neuroanatomy|
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 iliac crest 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.
The iliohypogastric nerve originates from the superior branch of the anterior ramus of spinal nerve L1 after this nerve receives fibers from T12 via the subcostal nerve. The inferior branch is the ilioinguinal nerve.
Lateral cutaneous branch
The lateral cutaneous branch ("iliac branch") pierces the internal and external oblique muscles immediately above the iliac crest and is distributed to the skin of the gluteal region, behind the lateral cutaneous branch of the subcostal nerve; the size of this branch bears an inverse proportion to that of the lateral cutaneous branch of the subcostal nerve.
When harvesting bone from the anterior iliac crest (AICBG), the lateral cutaneous branch of the Iliohypogastric nerve (L1) is most likely to be injured.
Anterior cutaneous branch
The anterior cutaneous branch ("hypogastric branch") continues onward between the abdominal internal oblique and transverse muscles.
It then pierces the internal oblique, becomes cutaneous by perforating the aponeurosis of the external oblique about 2.5 cm above the subcutaneous inguinal ring, and is distributed to the skin of the hypogastric region.
- Iliohypogastric_nerve at the Duke University Health System's Orthopedics program
- Atlas image: abdo_wall70 at the University of Michigan Health System - "Posterior Abdominal Wall, Dissection, Anterior View"
- Anatomy photo:35:05-0101 at the SUNY Downstate Medical Center - "Anterior Abdominal Wall: The Iliohypogastric and IlioInguinal Nerves"
- Anatomy photo:40:17-0101 at the SUNY Downstate Medical Center - "Posterior Abdominal Wall: Nerves of the Lumbar Plexus"
- Anatomy image:7055 at the SUNY Downstate Medical Center
- Anatomy image:7221 at the SUNY Downstate Medical Center
- Anatomy image:7257 at the SUNY Downstate Medical Center
- posteriorabdomen at The Anatomy Lesson by Wesley Norman (Georgetown University) (posteriorabdmus&nerves)