Mechanical Behavior Of Bone

Question 1

Bone is a type of __________ tissue

Answer 1

Connective

Question 2

Bone = ____ + ___________ ____ (ECM)

Answer 2

Cells + Extracellular matrix (ECM)

Question 3

What are the 3 types of bone cells?

Answer 3

Osteoblast
Osteocyte
Osteoclast

Question 4

Osteoblast

Answer 4

Deposition; growth, repair, remodeling

Question 5

Osteocyte

Answer 5

Maintenance

Question 6

Osteoclast

Answer 6

Resorption; unloading, repair, remodeling (“Pacmen”)

Question 7

Matrix composition of bone cells

Answer 7

Organic material

Question 8

Matrix composition of bone Extracellular matrix

Answer 8

Organic
Inorganic
Remaining tissue volume: water

Question 9

Bone ECM = organic material (__-___%)

Answer 9

30-35%

Question 10

Bone ECM = inorganic material (__-___%)

Answer 10

65-70%

Question 11

Organic material (2)

Answer 11

Protein
Vitamin C

Question 12

Lack of organic material results in ______ bones

Answer 12

Brittle bones

Question 13

Lack of organic material = brittle bones (_______)

Answer 13

Scurvy (found in sailors)

Question 14

Inorganic material (2)

Answer 14

Calcium
Vitamin D

Question 15

Lack of inorganic material results in ______ bones

Answer 15

Compliant

Question 16

Lack of inorganic material = compliant bones (_______, _________)

Answer 16

Rickets, osteomalacia; “bending a lot, but not breaking”

Question 17

Bone has both ______ and _______ mechanical behaviors.

Answer 17

Elastic; plastic

Question 18

Elastic mechanical behavior

Answer 18

Deforms with initial load in linear rate

Question 19

Elastic has 2 types of materials

Answer 19

Stiff materials
Compliant materials

Question 20

Stiff materials (elastic mechanical behavior): _________ deformation with ______ load.

Answer 20

Less; more

Question 21

Compliant materials (elastic mechanical behavior): _____ deformation with ______ load

Answer 21

More; less

Question 22

Plastic mechanical behavior

Answer 22

At a given load, the bone yields and continues to deform without additional load.

Question 23

2 types of plastic mechanical behavior

Answer 23

Brittle
Ductile

Question 24

Brittle

Answer 24

Breaks with load

Question 25

Ductile

Answer 25

Deforms with load

Question 26

Glass is an example of what kind of mechanical behavior?

Answer 26

Stiff/brittle

Question 27

Metal is an example of what kind of mechanical behavior?

Answer 27

Stiff/ductile (high load, won’t break)

Question 28

Rubber is an example of what kind of mechanical behavior?

Answer 28

Compliant/Brittle (stretch it too much, breakage)

Question 29

Putty is an example of what kind of mechanical behavior?

Answer 29

Compliant/ductile

Question 30

Bone strength

Answer 30

Maximum load at the failure point

Question 31

Bone stiffness or elasticity

Answer 31

Load required to deform the bone by a given amount Slope of load-deformation curve

Question 32

Toughness

Answer 32

Energy required to yield or fracture the bone; area under load-deformation curve

Question 33

Draw load deformation curve

Answer 33

Bone strength Elastic region, slope = stiffness Area = toughness Yield point (fracture begins) Plastic region

Question 34

Healthy bone (organic/inorganic)

Answer 34

30-35% organic 65-70% inorganic

Question 35

Brittle bone (organic/inorganic)

Answer 35

Less organic More inorganic

Question 36

Compliant bone (organic/inorganic)

Answer 36

More organic Less inorganic

Question 37

Which of the following pathologies is associated with lack of inorganic material in bone?

Answer 37

Rickets/osteomalacia