Day 4 (pg 155) Flashcards
What is the unusual about the cervical annulus fibrosus?
it lacks any lamellar or layered organization
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; the 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
Why is the posterior part of the lumbar annulus fibrosus more susceptible to rupture, herniation, prolapse, or protrusion?
the posterior margin of each lamellus is thin and the posterior longitudinal ligament is also less developed
What is the water concentration in the lumbar annulus fibrosus at birth and after thirty?
birth…78%; thirty…70%
What is the organizational pattern for glycosaminoglycans in lumbar annulus fibrosus?
they typically have a binding site for hyaluronic acid and are thus aggregated
What is the consequence of aggregated glycosaminoglycans in the lumbar annulus fibrosis?
the annulus fibrosus will retain water under deformation conditions
Which type of collagen is dominant in the annulus fibrosis?
collagen type I
What is the organization pattern for collagen fibers in the annulus fibrosus?
they are parallel with one another in a single lamellus 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 average angle of collagen fibers within the annulus fibrosus?
they average 50 to 60 degrees
What is the origin for the cells of the annulus fibrosus?
sclerotomites
What cell type is associated with the annulus fibrosus?
fibroblast and fibrocyte
What is the cartilage end plate derived from?
the epiphyseal plate
What part of the vertebral body will the cartilage end plate cover?
the cancellous bone at the top or bottom of the vertebral body
What is the principle type of collagen fiber within the cartilage end plate?
they type II collagen fiber
What is the direction of collagen fibers within the cartilage end plate?
collagen fibers are aligned anterior to posterior
What is the earliest indicator of intervertebral disc pathology or degeneration?
changes in the histology of the cartilage end plate
What part of the intervertebral disc is innervated?
the outer lamellae of the annulus fibrosus
What part of the cervical intervertebral disc is highly innervated?
the middle third of the annulus fibrosus
What are the types of receptor endings in the intervertebral disc?
nociceptors and proprioceptors
What is the relationship between size of the intervertebral disc and receptor endings?
the larger the disc, the greater the variety of receptor endings
What is the proposed function of receptor ending density in the anterior part of the intervertebral disc?
they provide feedback during extension
