Medicine & USMLE


  1. Osteoblasts
  2. Osteoclasts
  3. Osteocytes
  4. Spongy Bone
  5. Compact Bone
  6. Bone Structure
  7. Cartilage
  8. Joints
  9. Type 1 vs. Type 2 Muscle Fibers


Osteoblasts are a type of cell that builds new bone tissue. They do this by secreting a matrix of compounds, mostly consisting of the protein collagen. This matrix, also known as the osteoid, can then mineralize with calcium to form strong and dense tissue. 

Key Points

  • Osteoblasts
    • Form new bone by secreting collagen and inorganic compounds that serve as foundation/matrix for bone formation (osteoid)
      • Osteoid later mineralizes with calcium in the form of hydroxyapatite to form hard bone
    • Consume calcium to mineralize bone