anulus fibrosus


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anulus

 [an´u-lus] (pl. a´nuli) (L.)
a small ring or encircling structure; also spelled annulus.
anulus fibro´sus
1. fibrous ring of heart; any of four dense fibrous rings, one of which surrounds each of the major cardiac orifices.
2. fibrous ring of intervertebral disk; the circumferential ringlike portion of an intervertebral disk.
anulus of spermatozoon a dark ringlike structure at the posterior end of the middle piece of a spermatozoon. Called also ring centriole.

(right and left) fi·brous rings of heart

[TA]
two fibrous rings that surround atrioventricular orifices of the heart, providing attachment for the atrioventricular valve leaflets and maintaining patency of the orifices. As part of the fibrous skeleton of the heart, the fibrous rings also provide origin and insertion for the myocardium.

anulus fibrosus

an outer ring of collagen in an intervertebral disk arranged in a lamellar configuration that surrounds a wider zone of fibrocartilage.

an·u·lus fi·bro·sus of in·ter·ver·te·bral disc

(an'yū-lŭs fī-brō-sŭs in-tĕr-vĕr'tĕ-brăl disk) [TA]
The ring of fibrocartilage and fibrous tissue forming the circumference of the intervertebral disc; surrounds the nucleus pulposus, which can herniate when the anulus is diseased or injured.
Synonym(s): anulus fibrosus disci intervertebralis [TA] , anulus fibrosus (2) [TA] .

right and left fi·brous rings of heart

(rīt left fī'brŭs ringz hahrt)
Two fibrous rings that surround the atrioventricular orifices of the heart, providing attachment for the atrioventricular valve leaflets and maintaining patency of the orifices. As part of the fibrous skeleton of the heart, the fibrous rings also provide origin and insertion for the myocardium.
Synonym(s): anulus fibrosus (1) [TA] .
References in periodicals archive ?
Intrinsic's proprietary Barricaid anular prosthesis is a barrier that securely closes ruptures in the anulus fibrosus, the outer structure of the disc.
approximately 70%-90% water) exerts pressure in all directions on the surrounding rings of the anulus fibrosus through a process known as radial expansion [13,14].
As for other movements, axial rotation and/or side-bending will result in torsional forces applied to the lumbar IVDs, and resisted by the nature of the rings of the anulus fibrosus [13,14].
As a result, because the anular rings are not reinforced in the posterolateral direction, the anulus fibrosus is susceptible to injury, and common injury mechanisms involve excessive, highly forceful IVD loading or axial rotation.
Xclose provides a simple, convenient method for treating the compromised soft tissue of the anulus fibrosus.
These innovative systems provide efficient access for closure to facilitate the repair of the anulus fibrosus following a minimally invasive spinal microdiscectomy procedure.
The Xclose device is FDA cleared for soft-tissue approximation and the tools provide efficient access for closure of the anulus fibrosus following a minimally invasive microdiscectomy procedure.
Yonemura commented, "The Xclose device provides an unique new method for treating the weakened tissue of the anulus fibrosus following a lumbar discectomy procedure.