IVD

Question 1

there are ___ IVD given a numeric name based on the segment ABOVE, and they fxn in weight bearing and motion

Answer 1

23

Question 2

IVD constitute __-__% of vert column height

Answer 2

20-33

Question 3

• greatest IVD:VB height ratio is in the ___, least in the ___, and middle is the ___
• greater ratio indicates greater spinal segmental mobility

Answer 3

cervical
thoracic
lumbar

Question 4

___ __ of the IVD has 70-90% water content, which decreases with age

Answer 4

nucleus pulposis

Question 5

___ nuclei fill 30-50% of disc area in cross section, and they are more posterior than central, while ___ discs are less defined & the annulus is minimal on the lateral borders and only a thin strip in back

Answer 5

lumbar

cervical

Question 6

concentric laminated bands with same direction W/I a band but opposite directions in any two ADJACENT bands

Answer 6

annulus fibrosis

Question 7

annulus fibrosus bands seem to cross e/o obliquely, ea forming an angle of ___ to the VB

Answer 7

30 degrees

Question 8

annular fibers are firmly att’d to the ___ __ in the inner zone, while periph zone fibers attach to the VB via __ __

Answer 8

cartilaginous endplates

sharpey’s fibers

Question 9

the __ & __ reinforce the annular fibers, and the latter narrows from C-L

Answer 9

ALL

PLL

Question 10

the weakest area of the annulus is the ___ aspect, making it the MOST LIKELY spot for __ __ in the lumbar spine

Answer 10

posterolateral

disc herniation

Question 11

• the ___ portion of the cartilaginous end plate (CEP) is fairly impermeable while diffusion of nutrients occurs in the __ portion
• end plate supplies nucleus pulp w/ most of nutrition

Answer 11

outer

central

Question 12

no BV go directly to disc:

• annular fibers get blood supply from___
• nucleus pulposus gets supply from ___
• diffusion into disc from endplate

Answer 12

adjacent soft tissues

vertebral bodies

Question 13

IVD undergoes rapid degen and has limited self repair bc it is __ & __, but has increased vasc & innervated by sensory nerve fibers during disc degen (increased pain)

Answer 13

avascular

aneural

Question 14

overnight, the disc ___ which increases resistance to forces, but during the day fluid exits the disc, disc space ___ and there is a loss in seated height of ~20mm
-INCREASED ROM lumbar flex

Answer 14

expands

narrows

Question 15

the IVD is ___ and there is variation in loading in different parts of the disc

Answer 15

viscoelastic

Question 16

___ of nucleus pulposus results in ___ of annular fibers

Answer 16

compression

tension

Question 17

flexion results in __ of anterior disc and __ in posterior disc

Answer 17

compression

tension

Question 18

with age & biomech stresses, the disc becomes more ___ and causes decreased __, therefore an injured disc deforms more than a healthy one

Answer 18

fibrous

flexibilty

Question 19

___ varies with disc age, level, repetitive load

• decreases with successive loading
• stiffer when loaded rapidly, IVD less effective at shock absorb

Answer 19

hysteresis

Question 20

nucleus RESISTS __ forces and annular fibers have ___ strength, so they contain the nucleus by resisting “stretch”

Answer 20

compressive

tensile

Question 21

the DISC is more susceptible to failure in the area of ___ not compression

Answer 21

tension

Question 22

___ ___ caused from endplate fracture from significant axial load, nucleus migrates into the bodies

Answer 22

schmorl’s node

Question 23

• biomech behavior is dep on the state of ___, which is dependent on the __ of the disc
• by age 50, 97% of discs are degen

Answer 23

degeneration

age

Question 24

4 stages/types of disc herniation (see pic in notes slide 41)

Answer 24

1. nuclear herniation (w/i IVD)
2. bulge/prolapse (migrate outside IVD, no rupture)
3. extrusion
4. sequestration

Question 25

disc herniation is assoc with extreme deviated posture including these two motions, as well as with repeated loading

Answer 25

full flexion

lateral bending

Question 26

___ is caused by sudden compressive loading and lateral bending

Answer 26

sudden disc prolapse

Question 27

four common postural habits that increase lumbar spine flexion

Answer 27

crossed legs
squat on heels
lifting light weights
rapid lunging