Bone Physiology

• Composition of Bone

  living portion

  • cells (osteoblasts, osteoclasts, osteocytes)

  non - living portion

  • Calcium (Ca2+) ions
• bone cells

  • osteocytes - mature bone cells
  • osteoblasts - bone building cells
  • osteoclasts - bone destroying cells : break down bone matrix for remodeling and release of calcium into blood

  bone remodeling is performed by both osteoblasts and osteoclasts

  
• Bone Growth and Remodeling

  bones are remodeled in response to two factors

  • blood calcium levels
  • pull of gravity and muscles on the skeleton

  interstitial growth - bones grow in length

  appositional growth - bones grow in width