2. Bone Development and Calcification
Dr. Jack L. Haar
Department of Anatomy
Sanger Hall 9-064

3. Mechanisms of bone formation Intramembranous. 1
Mechanisms of bone formation Intramembranous 1. Ossification with mesenchymal origin Woven bone with low mineral content

4. b. Growth and appearance Spicules anastomose forming spongy bone

5. c. Conversion of spongy to compact bone. Lamellation continues
c. Conversion of spongy to compact bone Lamellation continues Primitive Haversian system lined by endosteum results

6. Ossification with connective tissue origin
Ossification with connective tissue origin Periosteal band forms in this way

7. Some bones develop entirely intramembranously
However, intramembranous ossification is partially responsible for development of most other bones

8. Endochondral bone formation
Hyaline cartilage model forms
Regressive changes in cartilage
Increased vascularization to perichondrium
Periosteal band forms
Periosteal bud supplies blood vessels and osteoblasts to interior

9. B. Endochondral bone formation
Bone is deposited on calcified cartilage
Looks like spongy bone

10. B. Endochondral bone formation
Newly formed bone looks like spongy bone
It formed on calcified cartilage spicules

11. Importance of Endochondral Ossification
Allows bones to grow in length
Due to interstitial growth of the cartilage

12. Primary center of Ossification in diaphysis
Forms the Epiphyseal plates
Cells form recognizable zonation

13. Resting zone – zone of reserve cartilage Zone of proliferation

14. Zone of maturation – cells hypertrophy

15. Zone of calcification, degeneration,

16. Area of bone ossification and resorption

17. In epiphysis (secondary center for ossification) Articular cartilage remains

18. Bone Growth Long bones grow in length from epiphyseal plate Long bones grow in width from periosteum or endosteum

19. Flat bone growth Deposition at the sutures Deposition on the convex surface and Resorption from the concave surface

20. Remodeling of bone: Deposition and resorption involved

21. III. Remodeling of bone

22. III. Remodeling of bone

23. III. Remodeling of bone

24. Remodeling of bone Occurs constantly as shown in microradiograph of bone from a healthy 19-year-old male

25. C. Fracture repair Fibroblasts and capillaries form granulation tissue Dense CT forms followed by cartilage Periosteum and endosteum form new bone Remodeling of bone

27. IV. Joints
A. Synarthroses – limited or no movement

28. IV. Joints
B. Diarthroses

29. B. Diarthrosis Synovial membrane (synovium)
Sqamous or cuboidal epithelial cells
Supplied with vessels nerves, lymphatics
Fibrous capsule continuous with periosteum

30. Synovial fluid Filtrate of blood High in Hyaluronic acid Lubricant for cartilage Provides nutrients to cartilage

31. http://www. path. uiowa. edu/virtualslidebox/ Table of Contents
Table of Contents Skeletal System Bone Developing #12 Endochondral ossification (no number)