The iliohypogastric nerve arises from the anterior ramus of the L1 nerve root of the lumbar plexus along with the ilioinguinal nerve. It a sensory nerve that provides lateral and anterior cutaneous branches supplying the posterolateral gluteal skin and skin in the pubic region.
The iliohypogastric nerve arises with the ilioinguinal nerve as a single trunk from the anterior ramus of the L1 nerve root of the lumbar plexus. This trunk enters the abdomen behind the medial arcuate ligament and runs anterolaterally parallel and superior to the iliac crests traversing the anterior surface of the quadratus lumborum muscle. The common trunk is short and the nerve soon divides in to iliohypogastric and ilioinguinal nerves at the lateral edge of the psoas muscle.
Course and branches
After branching from the common trunk with the ilioinguinal nerve, the iliohypogastric nerve continues along the anterior surface of the quadratus lumborum muscle posterior to the kidney.
The nerve pierces the transversus abdominis muscle coursing anteriorly between the transversus abdominis and internal oblique muscles. Above the iliac crest the iliohypogastric nerve gives off a lateral cutaneous branch to supply the posterolateral gluteal skin.
The remaining part of the iliohypogastric nerve (the anterior cutaneous branch) courses anteriorly to pierce the internal oblique muscle just above and slightly medial to the anterior superior iliac spine before turning obliquely downwards and medially becoming increasingly more superficial as it descends. Just superior to the superficial inguinal ring the anterior branch pierces the aponeurosis of the external oblique to distribute multiple cutaneous branches to the skin of the pubic region.
The iliohypogastric nerve gives off anterior and lateral cutaneous branches and supplies branches to the abdominal musculature along its course.
The lateral cutaneous branch arises from the iliohypogastric nerve above the iliac crest and supplies the upper part of the buttock behind the area supplied by the subcostal nerve.
The anterior cutaneous branch is the continuation of the iliohypogastric nerve anteriorly. Approximately 2.5 cm above the superficial inguinal ring the nerve terminates by supplying the skin over the lower part of the rectus abdominis and mons pubis.
Proximally the iliohypogastric nerve lies on the anterior surface of the quadratus lumborum muscle and posterior to the kidney. The ilioinguinal nerve travels inferiorly to the iliohypogastric nerve and has a more oblique course as it travels to the iliac crest typically traversing the iliacus muscle.
The iliohypogastric nerve has been shown to be absent in ~20% of lumbar plexi examined in cadaveric studies. Occasionally it was found that the iliohypogastric and ilioinguinal nerves remained conjoined (within a common epineurium) well after exiting the substance of the psoas major musculature although this variation was quite rare.
The size of the iliohypogastric nerve is inversely proportional to the size of the ilioinguinal nerve.
Abdominal and pelvic anatomy
- skeleton of the abdomen and pelvis
- muscles of the abdomen and pelvis
- anterior abdominal wall (surface anatomy)
- posterior abdominal wall
- pelvic floor
- spaces of the abdomen and pelvis
- anterior abdominal wall
- posterior abdominal wall
- peritoneal ligaments
- right supramesocolic space
- left supramesocolic space
- inframesocolic space
- supramesocolic space
- inguinal canal (mnemonic)
- Hesselbach triangle
- scrotal sac
- pelvic cavity
- abdominal and pelvic viscera
- gastro-oesophageal junction
- small intestine
- large intestine
- anal canal
- biliary tree
- adrenal gland
- organs of Zuckerkandl
- renal pelvis
- renal sinus
- avascular plane of Brodel
- urinary bladder
- male reproductive system
female reproductive system
- Mullerian duct
- uterine tubes
- variant anatomy
- gastrointestinal tract
- blood supply of the abdomen and pelvis
- inferior phrenic artery
- coeliac artery
- superior mesenteric artery
- suprarenal artery (middle suprarenal artery)
- renal artery (variant anatomy)
- gonadal artery (ovarian artery | testicular artery)
- inferior mesenteric artery
- lumbar arteries
- median sacral artery
common iliac artery
- external iliac artery
internal iliac artery (mnemonic)
- anterior division
- posterior division (mnemonic)
- variant anatomy
- abdominal aorta
- portal venous system
inferior vena cava
- hepatic veins
- renal vein
- common iliac vein
- variant caval anatomy
- inferior vena cava
- innervation of the abdomen and pelvis
- lumbar plexus
- lumbosacral trunk
- sciatic nerve
- superior gluteal nerve
- inferior gluteal nerve
- nerve to piriformis
- perforating cutaneous nerve
- posterior femoral cutaneous nerve
- parasympathetic pelvic splanchnic nerves
- pudendal nerve
- nerve to quadratus femoris and inferior gemellus
- nerve to internal obturator and superior gemellus
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