Iliohypogastric nerve | |
---|---|
Details | |
From | Lumbar plexus |
Innervates | Sensory: Skin over the lateral gluteal region and above the pubis [1] Motor: internal oblique and transverse abdominal muscles |
Identifiers | |
Latin | nervus iliohypogastricus |
TA98 | A14.2.07.003 |
TA2 | 6496 |
FMA | 16482 |
Anatomical terms of neuroanatomy |
The iliohypogastric nerve is a nerve that originates from the lumbar plexus that supplies sensation to skin over the lateral gluteal and hypogastric regions and motor to the internal oblique muscles and transverse abdominal muscles.
The iliohypogastric nerve originates from the superior branch of the anterior ramus of spinal nerve L1. [2] It also receives fibers from T12 via the subcostal nerve. [2] The branch below it is the ilioinguinal nerve. [2]
It emerges from the upper lateral border of the psoas major. [3] : 1148 It then crosses in front of the quadratus lumborum muscle to an area superior to the iliac crest. [4] It runs behind the kidneys. Just superior to the iliac crest, it pierces the posterior part of the transversus abdominis muscle and continues anteriorly in the abdominal wall between the transversus abdominis and internal oblique muscles. [3] : 1148
It divides into a lateral cutaneous branch and an anterior cutaneous branch between the transversus abdominis muscle and the internal oblique muscle.
The lateral cutaneous branch ("iliac branch") pierces the internal oblique muscles and the external oblique muscles immediately above the iliac crest. [4] It 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.
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.
The iliohypogastric nerve communicates with the subcostal nerve and ilioinguinal nerves. [2]
The iliohypogastric nerve may be absent in up to 20% of people. [5] Its fibres are instead carried on other nerves, such as the ilioinguinal nerve. [5]
The iliohypogastric nerve partially supplies the internal oblique muscles. [4] It also provides sensory innervation to the superior gluteal region and part of the suprapubic region. [4]
The iliohypogastric nerve may be damaged at the points where it passes through the internal oblique muscle and the external oblique muscles. [6] It is most often damaged by medical error. [4] It may also be damaged by a nerve lesion. [4]
The inguinal canal is a passage in the anterior abdominal wall on each side of the body, which in males, convey the spermatic cords and in females, the round ligament of the uterus. The inguinal canals are larger and more prominent in males.
The transverse abdominal muscle (TVA), also known as the transverse abdominis, transversalis muscle and transversus abdominis muscle, is a muscle layer of the anterior and lateral abdominal wall, deep to the internal oblique muscle. It is thought by most fitness instructors to be a significant component of the core.
The abdominal internal oblique muscle, also internal oblique muscle or interior oblique, is an abdominal muscle in the abdominal wall that lies below the external oblique muscle and just above the transverse abdominal muscle.
The abdominal external oblique muscle is the largest and outermost of the three flat abdominal muscles of the lateral anterior abdomen.
The intercostal nerves are part of the somatic nervous system, and arise from the anterior rami of the thoracic spinal nerves from T1 to T11. The intercostal nerves are distributed chiefly to the thoracic pleura and abdominal peritoneum, and differ from the anterior rami of the other spinal nerves in that each pursues an independent course without plexus formation.
The anterior superior iliac spine (ASIS) is a bony projection of the iliac bone, and an important landmark of surface anatomy. It refers to the anterior extremity of the iliac crest of the pelvis. It provides attachment for the inguinal ligament, and the sartorius muscle. The tensor fasciae latae muscle attaches to the lateral aspect of the superior anterior iliac spine, and also about 5 cm away at the iliac tubercle.
The internal iliac artery is the main artery of the pelvis.
The femoral nerve is a nerve in the thigh that supplies skin on the upper thigh and inner leg, and the muscles that extend the knee. It is the largest branch of the lumbar plexus.
The lumbar plexus is a web of nerves in the lumbar region of the body which forms part of the larger lumbosacral plexus. It is formed by the divisions of the first four lumbar nerves (L1-L4) and from contributions of the subcostal nerve (T12), which is the last thoracic nerve. Additionally, the ventral rami of the fourth lumbar nerve pass communicating branches, the lumbosacral trunk, to the sacral plexus. The nerves of the lumbar plexus pass in front of the hip joint and mainly support the anterior part of the thigh.
The ilioinguinal nerve is a branch of the first lumbar nerve (L1). It separates from the first lumbar nerve along with the larger iliohypogastric nerve. It emerges from the lateral border of the psoas major just inferior to the iliohypogastric, and passes obliquely across the quadratus lumborum and iliacus. The ilioinguinal nerve then perforates the transversus abdominis near the anterior part of the iliac crest, and communicates with the iliohypogastric nerve between the transversus and the internal oblique muscle.
The obturator nerve in human anatomy arises from the ventral divisions of the second, third, and fourth lumbar nerves in the lumbar plexus; the branch from the third is the largest, while that from the second is often very small.
The lateral cutaneous nerve of the thigh is a cutaneous nerve of the thigh. It originates from the dorsal divisions of the second and third lumbar nerves from the lumbar plexus. It passes under the inguinal ligament to reach the thigh. It supplies sensation to the skin on the lateral part of the thigh by an anterior branch and a posterior branch.
The lumbar arteries are arteries located in the lower back or lumbar region. The lumbar arteries are in parallel with the intercostals.
The subcostal nerve is a mixed motor and sensory nerve contributing to the lumbar plexus. It runs along the lower border of the twelfth rib, often gives a communicating branch to the first lumbar nerve, and passes under the lateral lumbocostal arch.
The subcostal arteries, so named because they lie below the last ribs, constitute the lowest pair of branches derived from the thoracic aorta, and are in series with the intercostal arteries.
The deep circumflex iliac artery is an artery in the pelvis that travels along the iliac crest of the pelvic bone.
The anterior divisions of the seventh, eighth, ninth, tenth, and eleventh thoracic intercostal nerves are continued anteriorly from the intercostal spaces into the abdominal wall; hence they are named thoraco-abdominal nerves.
The lumbar fascia is the lumbar portion of the thoracolumbar fascia. It consists of three fascial layers - posterior, middle, and anterior - that enclose two muscular compartments. The anterior and middle layers occur only in the lumbar region, whereas the posterior layer extends superiorly to the inferior part of the neck, and the inferiorly to the dorsal surface of the sacrum. The quadratus lumborum is contained in the anterior muscular compartment, and the erector spinae in the posterior compartment. Psoas major lies anterior to the anterior layer. Various superficial muscles of the posterior thorax and abdomen arise from the posterior layer - namely the latissimus dorsi, and serratus posterior inferior.
The following outline is provided as an overview of and topical guide to human anatomy:
This article incorporates text in the public domain from page 950 of the 20th edition of Gray's Anatomy (1918)
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