Intervertebral Disc: Annulus Fibrosus Flashcards
What is the appearance of the cervical annulus fibrosus?
A horse-shoe with the anterior margin thick and the lateral margins tapering to the uncinate processes
Posterior margin is thin
What compensates for the thinness of the posterior part of the cervical annulus fibrosus?
Posterior Longitudinal Ligament
What is the organization of the lumbar annulus fibrosus?
It has 12-14 concentric cylindrical lamellae
What is the water concentration in the lumbar annulus fibrosus at birth and after 30?
Birth: 78%
30: 70%
What is the organizational pattern for glycosaminoglycans in the lumbar annulus fibrosus?
They typically have a binding site for hyaluronic acid and are thus aggregated
Which type of collagen is dominant in the annulus fibrosus?
Collagen type I
What is the organizational pattern for collagen fibers in the annulus fibrosus?
They are parallel with one another in a single lamellas and angled.
What is the organization of collagen fibers between lamellae?
Collagen fibers will be angled in the opposite direction such that a spiral-counterspiral organization is observed.
What is the attachment site for collagen fibers within the annulus fibrosus?
Collagen fibers of the outer lamellae will become Sharpey’s fibers and penetrate the epiphyseal rims.
Collagen fibers of the inner lamellae will attach to the cartilaginous end plate
What is the origin for the cells of the annulus fibrosus?
Sclerotomites
What is the principal type of collagen fiber within the cartilage end plate?
Type II collagen
What is the direction of collagen fibers within the cartilage end plate?
Anterior to Posterior
What is the attachment site for collagen fibers of the inner lamellae of the annulus fibrosus?
Cartilaginous End Plate
