Exam 2 IVD Part 2

Question 1

Why is the IVD difficult to study in its entirety?

Answer 1

variation in loading in different sections of the disc

Question 2

What kind of force on the annular fibers results from compression of the nucleus pulposus?

Answer 2

tension

Question 3

What movement results in compression of the anterior disc and tension on the posterior disc?

Answer 3

flexion

Question 4

T/F: With age and exposure to biomechanical stresses, the IVD changes and becomes less fibrous.

Answer 4

False; becomes more fibrous

Question 5

T/F: as the IVD becomes more fibrous, the flexibiltiy is diminished and more pressure is exerted on the annulus and peripheral areas of the endplate.

Answer 5

True

Question 6

Does an injured disc deform more than a healthy one or less than?

Answer 6

injured disc deforms more

Question 7

T/F: all viscoelastic structures exhibit hysteresis ( the absorption or dissipation of energy by a distorted structure).

Answer 7

True

Question 8

What 3 things does hysteresis of the disc vary with?

Answer 8

age, level, and repetitive load

Question 9

Which discs have less hysteresis?

Answer 9

lower thoracic and upper lumbar

Question 10

T/F: hysteresis increases when successively loaded.

Answer 10

False; decreases

when loaded rapidly, it behaves stiffly and deforms less than when loaded slowly

Question 11

What kind of force is resisted by the nucleus pulposus? by the annular fibers?

Answer 11

compressive forces;

tensile forces

Question 12

What are the 3 types of loads imposed on the IVD?

Answer 12

compressive, tensile, and shear

Question 13

What kind of force is applied to the IVD during flexion, extension, and/or lateral bending?

Answer 13

compressive and tensile

Question 14

T/F: The disc is more susceptible to failure in the area of the forces of tension, not compression.

Answer 14

True

Question 15

How does a Schmorl’s node develop?

Answer 15

endplate fracture from significant axial load allowing the nucleus to migrate into the vertebral body

Question 16

What causes disc degeneration? What are the consequences?

Answer 16

supply and demand;

altered mechanics and inflammation

Question 17

T/F: biomechanical behavior is dependent upon the state of degeneration.

Answer 17

true

Question 18

T/F: the state of degeneration is independent of the age of the the disc.

Answer 18

False; is dependent upon the age of the disc

Question 19

T/F: by the age of 50, 100% of the lumbar discs are degenerated.

Answer 19

False; 97%

Question 20

Which segments have the most degeneration?

Answer 20

L3-L4, L4-L5, and L5-S1

Question 21

What are the 4 stages/types of disc herniation?

Answer 21

nuclear protrusion, disc bulge/prolapse, extrusion, and sequestration

Question 22

Which stage of disc herniation does the nucleus pulposus stay within the confines of the IVD?

Answer 22

nuclear protrusion

Question 23

During which stage of disc herniation does the nucleus migrat outsid of the IVD, but no rupture of the annular fibers exists?

Answer 23

Disc Bulge/Prolapse

Question 24

During which stage of disc herniation do the annular fibers tear?

Answer 24

extrusion

Question 25

During which stage of disc herniation do the contents of the nucleus pulposus move into the epidural space?

Answer 25

extusion

Question 26

During which stage of disc herniation do discal fragments break loose from the IVD and float freely in the CSF?

Answer 26

Sequestration

Question 27

What kind of posture is disc herniation associated with?

Answer 27

extreme deviated posture (full flexion or lateral bending)

Question 28

T/F: the disc bulges in the posterolateral direction of the concave side.

Answer 28

False; convex side (she corrected her notes in class)

Question 29

T/F: crossing the legs while sitting, squatting down on the heels, lifting light weights from the ground, and rapid lunging all increase extension of the lumbar spine.

Answer 29

False; all these actions increase flexion of the lumbar spine

Question 30

How long does resorption of extruded IVD material and annular scarring take?

Answer 30

several weeks to a year

Question 31

T/F: While recovering from IVD injury, patients should avoid exercise.

Answer 31

False; stay active but focus on low-impact activities

Question 32

T/F: Once a patient recovering from IVD injury is symptom-free the disc still needs time to heal.

Answer 32

True