ME 180/280; HB 177 Skeletal Development and Evolution
Study Questions
Chapter 6
1. Identify cancellous bone characteristics:
Where is it found?
What does its internal architecture look like?
How does it differ from cortical bone?
Draw the stress-strain curves for cortical bone and cancellous bone. Which is able to absorb more energy? Why? How can you tell from the graph?
What is happening in the plateau region of the graph?
2. Cancellous bone is full of voids. Explain how we can use an equivalent continuum model for cancellous bone that has no voids.
3. Define (give equations if appropriate):
Porosity:
Apparent Density:
Tissue Density:
Tissue Stress:
Continuum Stress:
4. High porosity means ______(high or low) apparent density.
Osteoporotic bone has a ______(higher or lower) porosity than normal bone.
5. What is the power law relationship for ultimate strength and apparent density?
6. What is the power law for elastic modulus and apparent density?
7. Draw the linear apposition curve as a function of daily stress stimulus.
8 . How is the change in bone apparent density related to the above apposition rate? Write the equation and explain.
9. In Figure 6.5 what parameters can change the attractor state (AS)? Make sure you understand all of the parameters in this figure.
10. If the attractor state increases, but the daily stress stimulus stays the same, will bone be deposited or resorbed?
11. T/F The internal architecture (arrangement) of cancellous bone changes if the magnitude of the load changes.
12. T/F The internal architecture (arrangement) of cancellous bone changes if the direction of the load changes.
13. Name two ways in which rb may affect the remodeling process. Which way causes temporary changes? Why? Why does one cause long-term changes?
14. What affects do implants have on bone architecture? Include biological and mechanical responses.