1. Bone Ossification

3. Endochondral ossification

4. Intramembranous ossification

5. Endochondral ossification

6. RZ PZ MZ HZ CZ Endochondral ossification

9. Proliferation zone Maturation zone Hypertrophy zone and calcification

11. Ossification zone

13. Osteoblast

14. Osteoclast Bone marrow

15. Bone trabeculum osteocyte osteoblast

17. Resorption zone

18. Osteoclast in depression called howship lacunae

19. osteoclast osteocyte

20. Primary Ossification Center Periosteal bone collar Periosteum

21. Bone marrow cavity (resorption zone)

22. Intramembranous ossification Periosteal bone collar

23. Intramembranous ossification ( Spongy bone) Mesenchyme conn. tissue trabeculum

25. No Secondary ossification center Primary ossification center

26. Secondary ossification

27. Secondary ossification center Blood vessels

28. Primary ossification center Secondary ossification center Epiphyseal plate

29. Secondary Ossification center