Intervertebral Disc: Annulus Fibrosus

Question 1

what is the appearance of the cervical annulus fibrosus?

Answer 1

a horse-shoe with the anterior margin thick and the lateral margins tapering to the uncinate processes; the posterior margin is thin

Question 2

what compensates for the thinness of the posterior part of the cervical annulus fibrosus?

Answer 2

posterior longitudinal ligament

Question 3

what is the organization of the lumbar annulus fibrosus?

Answer 3

it has 12-14 concentric cylindrical lamellae

Question 4

what is the water concentration in the lumbar annulus fibrosus at birth and after thirty?

Answer 4

birth…78%; thirty….70%

Question 5

what is the organizational pattern for glycosaminoglycans in the lumbar annulus fibrosus?

Answer 5

they typically have a binding site for hyaluronic acid and are thus aggregated

Question 6

which type of collagen is dominant in the annulus fibrosus?

Answer 6

collagen type I

Question 7

what is the organizational pattern for collagen fibers in the annulus fibrosus?

Answer 7

they are parallel with one another in a single lamellus and angled

Question 8

what is the organization of collagen fibers between lamellae?

Answer 8

collagen fibers will be angled in the opposite direction such that a spiral - counterspiral organization is observed

Question 9

what is the attachment site for collagen fibers within the annulus fibrosus?

Answer 9

collagen fibers of the outer lamellae will become Sharpey’s fibers and penetrate the epiphyseal rims; collage fibers of the inner lamellae will attach to the cartilaginous end plate

Question 10

what is the origin for the cells of the annulus fibrosus?

Answer 10

sclerotomites