The lateral arcuate ligament (also lateral lumbocostal arch and external arcuate ligament) is a
ligament
A ligament is the fibrous connective tissue that connects bones to other bones. It is also known as ''articular ligament'', ''articular larua'', ''fibrous ligament'', or ''true ligament''. Other ligaments in the body include the:
* Peritoneal li ...
under the
diaphragm
Diaphragm may refer to:
Anatomy
* Thoracic diaphragm, a thin sheet of muscle between the thorax and the abdomen
* Pelvic diaphragm or pelvic floor, a pelvic structure
* Urogenital diaphragm or triangular ligament, a pelvic structure
Other
* Diap ...
that arches across the upper part of the
quadratus lumborum muscle. It is traversed by the
subcostal nerve
The subcostal nerve (anterior division of the twelfth thoracic nerve) is larger than the others. 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 lumbocost ...
,
artery and
vein.
Structure
The lateral arcuate ligament runs from the front of the transverse process of the first
lumbar vertebra, and, laterally, to the tip and lower margin of the twelfth
rib
In vertebrate anatomy, ribs ( la, costae) are the long curved bones which form the rib cage, part of the axial skeleton. In most tetrapods, ribs surround the chest, enabling the lungs to expand and thus facilitate breathing by expanding the ches ...
.
It forms an arch over the
quadratus lumborum muscle.
Variations
The lateral arcuate ligament is commonly described in anatomy textbooks as attaching at the first lumbar vertebra (L1).
However, other instances have been found in
cadaver
A cadaver or corpse is a dead human body that is used by medical students, physicians and other scientists to study anatomy, identify disease sites, determine causes of death, and provide tissue to repair a defect in a living human being. Stud ...
studies with attachments at either the second (L2) or third (L3) lumbar vertebra.
In around 5% of people, inferolateral extensions of the lateral arcuate ligaments, such as thickened nodular areas, are found adjacent to the lateral diaphragmatic surface which can be visualized with
computed tomography
A computed tomography scan (CT scan; formerly called computed axial tomography scan or CAT scan) is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers ...
(CT) scans.
History
The lateral arcuate ligaments were described by
Galen, as early as AD 177.
This was found in his animal dissections performed as part of his
Rome lectures, collected in ''De Anatomicus Administrationibus''.
[Galen, Singer C (Trans.) "Galen on anatomical procedures: de Anatomicis administrationibus", Oxford University Press, 1956, p14]
/ref>
See also
* Medial arcuate ligament
The medial arcuate ligament (also medial lumbocostal arch and internal arcuate ligament) is a tendinous fascia that arches over the psoas major muscle as it passes posterior the diaphragm.
Structure
The medial arcuate ligament is an arch in the f ...
* Median arcuate ligament
References
External links
* - "The abdominal surface of the diaphragm."
* ()
{{Authority control
Ligaments of the torso
Thoracic diaphragm