Week 4

Question 1

two types of bone

Answer 1

Compact

Trabecular (spongy)

Question 2

Define epiphysis

Answer 2

area within the bone that contains spongy bone

Question 3

Define diaphysis

Answer 3

Area within the bone that contains compact bone

Question 4

Define and explain Osteo Blasts

Answer 4

Cells that form new bone

numerical variable is a variable where the measurement or number has a numerical meaning.

Question 5

Define and explain Osteo Clasts

Answer 5

• Osteoclasts removes bone tissue by removing the mineral matrix of the bone and dissolving the collagen part of the bone and dissolves it into the blood
  
  • Unmineralized bone (osteoid) is protected against osteoclastic resportion

Question 6

Bone strength is influenced by what 4 factors

Answer 6

• Bone mineral density
  
  • Bone mineral content
  • Size
  • Geometry

Question 7

Define load-deformation curve

Answer 7

A curve showing the relationship between the stress or load on a structure, structural member, or a specimen and the strain or deformation that results.

Question 8

Define stress stain curve

Answer 8

Load-deformation curve but removes the cofounding effects of geometry and size of the material

Question 9

What does the are under the curve of a load-deformation curve represent

Answer 9

Absorbed energy

Question 10

What the linear segment in a load-deformation curve represent

Answer 10

Elastic region

Question 11

What does the plateau represent in a load-deformation curve

Answer 11

Plastic region

Question 12

What does the slope of the load deformation curve represent

Answer 12

Material stifness

Question 13

How much tolerance can a cortical bone take for compression, tension and shearing

Answer 13

Compression - 190Mpa
Tension - 130
shearing - 70

Question 14

How much tolerance can a trabecular bone take for compression and tension

Answer 14

Compression - 50

Tension - 8Mpa

Question 15

Define anisotropic behaviour of bone

Answer 15

Differences in strength depending on how we load the bone

Question 16

Bones are strongest…..

Answer 16

if you load them fast

Question 17

What causes stress fractures

Answer 17

When remodeling can’t keep up with loading related damage

Question 18

What is wollf’s law

Answer 18

Bone in a healthy person will adapt to the loads under which it is placed

Question 19

Define growth in regards to wollf’s law

Answer 19

• The cartilaginous nature of the growth or epiphyseal plate renders it prone to damage during period of growth

Question 20

Define avulsion fractures

Answer 20

• Fractures at the weak/est points in the bone

Question 21

What are 5 non-modifiable risk factors of osteoporosis

Answer 21

• Female sex, age > 70 years, being Caucasian or Asian, early onset of menopause, longer postmenopausal interval

Question 22

What are 7 modifiable risk factors of osteoporosis

Answer 22

• Lack of weight bearing exercise, smoking, alcohol abuse, XS caffeine consumption, low dietary Ca2+, lack of sunlight

Question 23

What are the two types of bone loading

Answer 23

Static

Dynamic

Question 24

Define static loading

Answer 24

• Static = constant

Question 25

Define dynamic loading

Answer 25

• Dynamic = intermittent
  
  • High rates of intermittent deformation
  • Drives fluid back and forth through lacunar-canalicular network

Question 26

What type of bone loading stimulates osteogenesis

Answer 26

Dynamic