annulus fibrosus


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annulus fibrosus

The tough fibrous outer zone of the intervertebral disc that normally retains the soft inner nucleus pulposus. Weakness of the annulus fibrosus allows prolapse of the pulpy centre in the condition inaccurately known as ‘slipped disc’.

annulus fibrosus

the fibrous ring which encircles each intervertebral disc.

annulus fibrosus

fibrocartilage ring forming the outer part of an intervertebral disc (see disc)
References in periodicals archive ?
Nucleus pulposus and annulus fibrosus regions were identified, several regions of interest were chosen, and their ADC values were obtained.
Disk calcification occurs primarily in the annulus fibrosus and is thought to be due to dystrophic calcification of the abnormal connective tissue.
The intervertebral disc consists of a central gelatinous core; the nucleus pulposus encircled by concentric layers of a densely fibrous connective tissue, the annulus fibrosus.
The annulus fibrosus, the outer layer of the intervertebral discs, restrains the displacement of the nucleus pulposus.
In 1929, Schmorl reported his observation of "nodules" associated with the disc; he believed them to be a result of a prolapsed nucleus pulposus and associated with a degenerative or traumatized annulus fibrosus.
Ayturk et al [3] used continuum approach for modeling intervertebral disk's annulus fibrosus to investigate the effects of degenerative disease and disks were tested under planar biaxial tension.
The second mechanism, mechanical retraction of the herniated disc, is a theoretical assumption expected to occur when the disc herniation protrudes through the annulus fibrosus by protecting anatomical relation.
In the anatomical three-column model described by Denis (5), the anterior column includes the anterior longitudinal ligament and the anterior half of the vertebral body and the annulus fibrosus, the middle column includes the posterior half of the vertebral body and the annulus fibrosus along with the posterior longitudinal ligament, and the posterior column includes the bone and ligamentous structures posterior to the posterior longitudinal ligament.
Objective: We hypothesize that within the intervertebral disc (IVD), a niche exists comprising the nucleus pulposus and the inner layer of the annulus fibrosus and the cartilage endplate.
The disc joint is composed of three major parts: cartilaginous vertebral endplates that cap the bodies of the vertebrae, a fibrous annulus fibrosus that is located circumferentially between the vertebral bodies, and a thick gel-like nucleus pulposus in the center bounded by the fibers of the annulus fibrosus.
The Annulus Fibrosus is densely packed with rings or highly organized collagen type I fibril sheets or lamellae, in which fibrocytes are distribu- ted.
Migration of the Nucleus Pulposus intra-durally requires perforation of the Annulus Fibrosus and the posterior longitudinal ligament.