Physiology -Notes- Bone Growth

Bone Growth

• Bones grow from the epiphyseal plate during infancy and youth
  
• Facial bones continue to grow until your demise
  
• Replacement of cartilage cells by bone cells only on the sides of the diaphysis
  
• Controlled by sex & growth hormones
  
• Bone growth is completed at 25 years in males and 19 years in females
  

~3 Different Zones~

1.) Growth Zone: cartilage undergoes mitosis, push up on epiphyseal plate

2.) Transformation Zone: older cells begin to break down (hypertrophy) and enlarge

-These cells begin to calcify

-Cartilage turned into bone

3.) Osteogenic Zone: formation of medullary cavity

~Growth is Dependent on 4 Factors~

1.) Adequate Minerals: Ca²⁺, B, Mn

2.) Hormones: thyroid, growth, sex, parathyroid, calcitonin

3.) Vitamins: A, B₁₂, C, D

4.) Exercise: weight bearing stress