Exam 2 IVD Part 1

Question 1

T/F: There are 23 discs in the human adult given a numeric name based on the segment below.

Answer 1

False; segment above

Question 2

T/F: The unique structure of the IVD allows for its function in both weight-bearing and motion.

Answer 2

True

Question 3

How much of the height of the vertebral column is composed of the discs?

Answer 3

20-33%

Question 4

What are the 3 parts of the IVD?

Answer 4

nucleus pulposus, annulus fibrosus, and cartilaginous end plates

Question 5

T/F: A greater ratio of IVD disc height to vertebral body height means less spinal segmental mobility.

Answer 5

False; greater disc to vertebral body height ratio=greater mobility (more disc, more movement)

Question 6

Where is the ratio of disc to vertebral body the greatest? the least?

Answer 6

cervical;
thoracic
(most mobility in cervicals)

Question 7

Generally, how much of the nucleus pulposus is composed of water? When is the water content at its highest?

Answer 7

70-90%;
at birth (dry out over time)

Question 8

Bigger discs have more capacity to change size. What is this known as?

Answer 8

creep

Question 9

T/F: Lumbar IVD nuclei are more anterior than central.

Answer 9

false; more posterior than central

Question 10

How much of the total disc area is compose of nuclei in the lumbar IVDs?

Answer 10

30-50%

Question 11

T/F: Cervical discs are less defined with only a thin strip of annulus in the back.

Answer 11

True

Question 12

What part of the IVD is composed of fibrous tissue in concentric laminated bands?

Answer 12

Annulus Fibrosus

Question 13

T/F: Fibers in adjacent bands of the annulus fibrosus run parallel to each other.

Answer 13

False; same direction within a single band, but opposite directions in any two adjacent bands

Question 14

T/F: Annular fibers form an angle of about 45 degrees to the vertebral body.

Answer 14

False; about 30 degrees

Question 15

What are annular fibers attached to?

Answer 15

cartilaginous endplates in the inner zone, and the vertebral body in the peripheral zone

Question 16

What are the especially strong fibers called that attach the annulus to the vertebral body?

Answer 16

Sharpey’s fibers

Question 17

T/F: the ALL and the PLL reinforce the annular fibers,.

Answer 17

True

Question 18

T/F: the PLL widens from cervical to lumbars to compensate for the increasing size of the vertebral bodies.

Answer 18

False; PLL narrows inferiorly until it covers only about 50% of the lower lumbar discs

Question 19

What is the weakest and hence the most likely to be injured part of the annulus?

Answer 19

posterolateral aspect

Question 20

What is the most lilely spot for a disc herniation in the lumbar spine?

Answer 20

posterolateral aspect

Question 21

t/F: fibers of the annulus attach the endplate to the disc.

Answer 21

True

Question 22

T/F: the central portion of the cartilaginous end plate is fairly impermeable and thus, diffusion of nutrients occurs in the outer portion.

Answer 22

False; vice-versa

Question 23

T/F: the end plate supplies the nucleus pulposus with most (or all) of its nutrition.

Answer 23

True

Question 24

T/F: the cartilaginous end plates help to prevent the vertebral bodies from hypertrophy.

Answer 24

False; prevent pressure atrophy

Question 25

T/F: the cartilaginous end plates maintain the nuclear and annular borders.

Answer 25

True

Question 26

T/F: Typical, healthy discs are well vascularized.

Answer 26

False; avascular

Question 27

Where do annular fibers receive their blood supply? nucleus pulposus

Answer 27

adjacent soft tissues;

vertebral bodies

Question 28

T/F: nutrients can diffuse into the disc from the end plates.

Answer 28

True

Question 29

T/F: A typical, healthy IVD is avascular and aneural.

Answer 29

True

Question 30

T/F: The IVD undergoes rapid degeneration and has limited self repair.

Answer 30

True

Question 31

T/F: While sleeping, IVDs have an increased hydrostatic pressure and an increased osmotic pressure which increases the resistance to forces.

Answer 31

False; lower hydrostatic pressure, higher osmotic pressure

Question 32

T/F: During daily activity (daytime) fluid exits the disc resulting disc space narrowing and a loss of seated height of about 40mm.

Answer 32

False; 20mm

Question 33

What happens to lumbar flexion ROM as the disc space narrows throughout the day?

Answer 33

lumbar flexion increases up to 50%