Ligamenta flava
Encyclopedia
The ligamenta flava are ligaments which connect the lamina
e of adjacent vertebrae, all the way from the axis
to the first segment of the sacrum
(C2
to S1
). They are best seen from the interior of the vertebral canal; when looked at from the outer surface they appear short, being overlapped by the laminæ.
Each ligament consists of two lateral portions which commence one on either side of the roots of the articular processes
, and extend backward to the point where the laminæ meet to form the spinous process
; the posterior margins of the two portions are in contact and to a certain extent united, slight intervals being left for the passage of small vessels. Each consists of yellow elastic tissue, the fibers of which, almost perpendicular in direction, are attached to the anterior surface of the lamina above, some distance from its inferior margin, and to the posterior surface and upper margin of the lamina below. In the cervical region the ligaments are thin, but broad and long; they are thicker in the thoracic region, and thickest in the lumbar
region.
Their marked elasticity serves to preserve the upright posture, and to assist the vertebral column in resuming it after flexion
. The elastin prevents buckling of the ligament into the spinal canal during extension, which would cause canal compression. Hypertrophy
of this ligament may cause spinal stenosis
because it lies in the posterior portion of the vertebral canal.
Lamina of the vertebral arch
The laminæ are two broad plates, extending dorsally and medially from the pedicles, fusing to complete the roof of the vertebral arch.Their upper borders and the lower parts of their anterior surfaces are rough for the attachment of the ligamenta flava....
e of adjacent vertebrae, all the way from the axis
Axis (anatomy)
In anatomy, the second cervical vertebra of the spine is named the axis or epistropheus.It forms the pivot upon which the first cervical vertebra , which carries the head, rotates....
to the first segment of the sacrum
Sacrum
In vertebrate anatomy the sacrum is a large, triangular bone at the base of the spine and at the upper and back part of the pelvic cavity, where it is inserted like a wedge between the two hip bones. Its upper part connects with the last lumbar vertebra, and bottom part with the coccyx...
(C2
Axis (anatomy)
In anatomy, the second cervical vertebra of the spine is named the axis or epistropheus.It forms the pivot upon which the first cervical vertebra , which carries the head, rotates....
to S1
Sacrum
In vertebrate anatomy the sacrum is a large, triangular bone at the base of the spine and at the upper and back part of the pelvic cavity, where it is inserted like a wedge between the two hip bones. Its upper part connects with the last lumbar vertebra, and bottom part with the coccyx...
). They are best seen from the interior of the vertebral canal; when looked at from the outer surface they appear short, being overlapped by the laminæ.
Each ligament consists of two lateral portions which commence one on either side of the roots of the articular processes
Articular processes
The articular processes or zygapophyses of a vertebra, two superior and two inferior, spring from the junctions of the pedicles and laminæ...
, and extend backward to the point where the laminæ meet to form the spinous process
Spinous process
The spinous process of a vertebra is directed backward and downward from the junction of the laminae , and serves for the attachment of muscles and ligaments. In animals without an erect stance, the process points upward and may slant forward or backward...
; the posterior margins of the two portions are in contact and to a certain extent united, slight intervals being left for the passage of small vessels. Each consists of yellow elastic tissue, the fibers of which, almost perpendicular in direction, are attached to the anterior surface of the lamina above, some distance from its inferior margin, and to the posterior surface and upper margin of the lamina below. In the cervical region the ligaments are thin, but broad and long; they are thicker in the thoracic region, and thickest in the lumbar
Lumbar
In tetrapod anatomy, lumbar is an adjective that means of or pertaining to the abdominal segment of the torso, between the diaphragm and the sacrum ...
region.
Their marked elasticity serves to preserve the upright posture, and to assist the vertebral column in resuming it after flexion
Flexion
In anatomy, flexion is a position that is made possible by the joint angle decreasing. The skeletal and muscular systems work together to move the joint into a "flexed" position. For example the elbow is flexed when the hand is brought closer to the shoulder...
. The elastin prevents buckling of the ligament into the spinal canal during extension, which would cause canal compression. Hypertrophy
Hypertrophy
Hypertrophy is the increase in the volume of an organ or tissue due to the enlargement of its component cells. It should be distinguished from hyperplasia, in which the cells remain approximately the same size but increase in number...
of this ligament may cause spinal stenosis
Spinal stenosis
Lumbar spinal stenosis is a medical condition in which the spinal canal narrows and compresses the spinal cord and nerves at the level of the lumbar vertebra. This is usually due to the common occurrence of spinal degeneration that occurs with aging. It can also sometimes be caused by spinal disc...
because it lies in the posterior portion of the vertebral canal.