What is the primary growth front? What is the secondary growth front? What happens when they approach each other? What happens to both once an individual reaches maturity? 3. What is angiogenesis? What are 4 factors that promote it? 5. What are two of the important genetic and epigenetic factors that influence the pattern formation process? 6. What is the premise of the Heuter-Volkmann Law? 7. What did Pauwels propose for stresses associated with tendon development, bone regeneration, and endochondral ossification? What aspects of his beliefs are contrary to the authors?