ARTHOLOGY OF THE VERTEBRAL COLUMN - intervertebral disc Flashcards
In the fetus, which vertebral levels will demonstrate intervertebral discs?
those between C2 and Co1 inclusive
What is the number of true intervertebral discs identified in the adult?
twenty-three
In the adult, which vertebral levels will demonstrate a true intervertebral disc?
those between C2 and S1 inclusive
What is the percent of intervertebral disc height contribution to the length of each region of the vertebral column?
cervical 22-25%
thoracic 20%
lumbar 33%
What si the effect of aging on the intervertebral disc nucleus pulposus?
it becomes more fibrous as water and proteoglycan concentrations diminish
What is the cervical nucleus pulposus composed of?
fibrocartilage
What is the consequence of non-aggregated glycosaminoglycans in the lumbar nucleus pulposus?
the nucleus pulposus will lose water under deformation conditions
What cell is associated with the nucleus pulposus until about age eleven?
notochord cells
Which type of collagen is dominant in the nucleus pulposus?
collagen type II
What is 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 is the organization of the lumbar annulus fibrosus?
it has 12-14 concentric cylindrical lamellae
What is the consequence of aggregated glycosaminoglycans in the lumbar annulus givrosus?
the annulus fibrosus will retain water under deformation conditions
Which type of collagen is dominant in the annulus fibrosus?
collagen type I
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 organizational pattern for collagen fibers in the annulus fibrosus?
they are parallel with one another in a single lamellus and angled
What is the average angle of collagen fibers within the annulus fibrosus?
they average 50 to 60 degrees
What is the principal type of collagen fiber within the cartilage end plate?
the type II collagen fiber
What is the direction of collagen fibers within the cartilage end plate?
collagen fibers are aligned anterior to posterior
What cell type is associated with the cartilage end plate?
chondrocytes
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 the “growth plate”
the transition zone
What part of the intervertebral disc is innervated?
the outer lamellae 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
What forms the posterior neural plexus of the vertebral column?
the sinu-vertebral nerve (sinus vertebral nerve, recurrent meningeal nerve
What forms the anterior neural plexus of the vertebral column?
fibers from the ventral primary ramus
What is the name given to the white ramus communicans which becomes embedded within the annulus fibrosus of the intervertebral disc?
the paradiscal ramus communicans
What innervates the outer lamellae of the annulus fibrosus at the lateral part of the intervertebral disc?
fibers from the ventral primary ramus, fibers from the white ramus communicans, fibers from the paradiscal ramus communicans, fibers from the gray ramus communicans
What structure is formed following migration of sclerotomes to surround the notochord?
the perichordal blastema
What is formed within the perichordal blastema between the sclerotomites?
the intrasclerotomal fissure or fissure of von Ebner
What does the intrasclerotomal fissure or fissure of von Ebner become?
the perichordal disc
What part of the intervertebral disc will the notochord form?
the nucleus pulposus
What part of the intervertebral disc will the perichordal disc form?
the annulus fibrosus
What is the earliest indicator of the position of the adult intervertebral disc?
the intrasclerotomal fissure or fissure of von Ebner
