The thoracolumbar fascia (lumbodorsal fascia or thoracodorsal fascia) is a deep investing membrane throughout most of the posterior thorax and abdomen although it is a thin fibrous lamina in the

thoracic The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the crea ...

region. Above, it is continuous with a similar investing layer on the back of the neck—the

nuchal fascia The nuchal fascia is a fascia covering the autochthonous musculature of the neck as a part of the cervical fascia The cervical fascia is fascia found in the region of the neck. It usually refers to the deep cervical fascia. However, there is a ...

. It is formed of longitudinal and transverse fibers that bridge the aponeuroses of

internal oblique 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. Structure Its fibers ...

and

transversus 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 (front and side) abdominal wall which is deep to (layered below) th ...

, costal angles and iliac crest laterally, to the vertebral column and sacrum medially. In doing so, they cover the paravertebral muscles. It is made up of three layers, anterior, middle, and posterior. The anterior and middle layers insert onto the

transverse processes The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic i ...

of the vertebral column while the posterior layer inserts onto the tips of the spinous processes, hence it is indirectly continuous with the

interspinous ligaments The interspinous ligaments (interspinal ligaments) are thin and membranous ligaments, that connect adjoining spinous processes of the vertebra in the spine. They extend from the root to the apex of each spinous process. They meet the ligamenta fl ...

. The anterior layer is the thinnest and the posterior layer is the thickest. Two spaces are formed between these three layers of the

fascia A fascia (; plural fasciae or fascias; adjective fascial; from Latin: "band") is a band or sheet of connective tissue, primarily collagen, beneath the skin that attaches to, stabilizes, encloses, and separates muscles and other internal organs. ...

. *

Psoas major The psoas major ( or ; from grc, ψόᾱ, psóā, muscles of the loins) is a long fusiform muscle located in the lateral lumbar region between the vertebral column and the brim of the lesser pelvis. It joins the iliacus muscle to form the iliop ...

lies anterior to the anterior layer, with the anterior fascia of this muscle being continuous with the vertebral body and thus the

anterior longitudinal ligament The anterior longitudinal ligament is a ligament that runs down the anterior surface of the spine. It traverses all of the vertebral bodies and intervertebral discs on their ventral side. It may be partially cut to treat certain abnormal curvatur ...

. * Between the anterior and middle layer lies the

quadratus lumborum The quadratus lumborum muscle, informally called the ''QL'', is a paired muscle of the left and right posterior abdominal wall. It is the deepest abdominal muscle, and commonly referred to as a back muscle. Each is irregular and quadrilateral in sh ...

muscle. * The erector spinae muscles and the

transversospinales muscles The transversospinales are a group of muscles of the human back. Their combined action is rotation and extension of the vertebral column. These muscles are small and have a poor mechanical advantage for contributing to motion. They include: * the ...

are then enclosed between the middle and posterior layers. * Various superficial muscle layers on the posterior thorax and abdomen then arise from the posterior layer. These primarily include

latissimus dorsi The latissimus dorsi () is a large, flat muscle on the back that stretches to the sides, behind the arm, and is partly covered by the trapezius on the back near the midline. The word latissimus dorsi (plural: ''latissimi dorsorum'') comes from L ...

and

serratus posterior inferior The serratus posterior inferior muscle, also known as the posterior serratus muscle, is a muscle of the human body. Structure The muscle is situated at the junction of the thoracic and lumbar regions. It has an irregularly quadrilateral form, ...

References

External links

* - "Thoracolumbar Fascia, Dissection, Posterior View" * - "Trunk, Transverse MRI Showing Lamellae of the Thoracolumbar Fascia" {{Authority control Thorax (human anatomy) Fascial spaces of the head and neck

See also

References

External links