Intervertebral Disc

Question 1

What is the number of true intervertebral discs identified in the adult?

Answer 1

twenty-three

Question 2

In the adult, which vertebral levels will demonstrate a true intervertebral disc?

Answer 2

those between C2 and S1 inclusive

Question 3

What is the intervertebral disc histologically composed of?

Answer 3

cells, collagen fibers, and a hydrated proteoglycan gel

Question 4

What is the cervical nucleus pulposus composed of?

Answer 4

fibrocartilage

Question 5

What is the water concentration in the lumbar nucleus pulposus at birth and after thirty?

Answer 5

birth…88%; thirty…70%

Question 6

What is the consequence of non-aggregated glycosaminoglycans in the lumbar nucleus pulposus?

Answer 6

the nucleus pulposus will lose water under deformation conditions

Question 7

What cell is associated with the nucleus pulposus until about age eleven?

Answer 7

notochord cells

Question 8

What cells are associated with the mature nucleus pulposus?

Answer 8

reticulocyte-fibroblast and chondroblast

Question 9

Which type of collagen is dominant in the nucleus pulposus?

Answer 9

collagen type II

Question 10

What general tissue location is described as having an abundance of collagen type II fibers?

Answer 10

cartilage

Question 11

What is the role of collagen type II fibers based on locations where it is dominant?

Answer 11

it appears to be related to tissues having a deformation-reformation ability

Question 12

What is the appearance of the cervical annulus fibrosus?

Answer 12

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

Question 13

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

Answer 13

posterior longitudinal ligament

Question 14

What is the organization of the lumbar annulus fibrosus?

Answer 14

it has the 12-14 concentric cylindrical lamellae

Question 15

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

Answer 15

birth…78%; thirty…70%

Question 16

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

Answer 16

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

Question 17

Which type of collagen is dominant in the annulus fibrosus?

Answer 17

collagen type I

Question 18

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

Answer 18

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

Question 19

What is the organization of collagen fibers between lamellae?

Answer 19

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

Question 20

What is the average angle of collagen fibers within the annulus fibrosus?

Answer 20

they average 50 to 60 degrees

Question 21

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

Answer 21

sclerotomites

Question 22

What part of the vertebral body will the cartilage end plate cover?

Answer 22

the cancellous bone at the top or bottom of the vertebral body

Question 23

What is the principal type of collagen fiber within the cartilage end plate?

Answer 23

the type II collagen fiber

Question 24

What is the direction of collagen fibers within the cartilage end plate?

Answer 24

collagen fibers are aligned anterior to posterior

Question 25

What is the earliest indicator of intervertebral disc pathology or degeneration?

Answer 25

changes in the histology of the cartilage end plate

Question 26

What is the area of maximum metabolic activity in the intervertebral disc?

Answer 26

the transition zone

Question 27

What part of the intervertebral disc is innervated?

Answer 27

the outer lamellae of the annulus fibrosus

Question 28

What part of the cervical intervertebral disc is highly innervated?

Answer 28

the middle third of the annulus fibrosus

Question 29

What are the types of receptor endings in the intervertebral disc?

Answer 29

nociceptors and proprioceptors

Question 30

What is the relationship between size of the intervertebral disc and receptor endings?

Answer 30

The larger the disc, the greater the variety of receptor endings

Question 31

The recurrent meningeal/sinu-vertebral/sinus vertebral nerve has typically been shown to originate from what source?

Answer 31

the gray ramus communicans

Question 32

What part of the intervertebral disc is innervated by the recurrent meningeal/sinu-vertebral/sinus vertebral nerve?

Answer 32

the outer lamella of the annulus fibrosus at the posterior part of the intervertebral disc

Question 33

What forms the anterior neural plexus of the vertebral column?

Answer 33

fibers from the ventral primary ramus

Question 34

What forms the lateral neural plexus of the vertebral column?

Answer 34

fibers from the ventral primary ramus, fibers from the white ramus communicans, fibers from the paradiscal ramus communicans, fibers from the grey ramus communicans

Question 35

What is the name given to the white ramus communicans which becomes embedded within the annulus fibrosus of the intervertebral disc?

Answer 35

the paradiscal ramus communicans

Question 36

What part of the intervertebral disc is innervated by fibers from the paradiscal ramus communicans?

Answer 36

the outer lamellae of the annulus fibrosus at the lateral part of the intervertebral disc

Question 37

What is formed withing the perichordal blastema between the sclerotomites?

Answer 37

the intrasclerotomal fissure of fissure of von Ebner

Question 38

What does the intrasclerotomal fissure of fissure of von Ebner become?

Answer 38

the perichordal disc

Question 39

What will the dense sclerotomite become?

Answer 39

the upper part of the vertebral segment forming below