1. BONE FORMATION, GROWTH, AND REPAIR NOTES

2. Osteogenesis: Formation of Your Bones
Compare the two types of bone formation.
Endochondral Ossification

3. Ossification: The process of forming bone.
The cartilage or membranes are ultimately replaced with bone tissue.

4. Endochondral Ossification Endo=within Chondral=cartilage
What type of bone is this?
Long
Short
Flat
Irregular
Sesamoid

5. Intramembranous bone Intra=within
What type of bone is this?
Long
Short
Flat
Irregular
Sesamoid

6. Formation begins with….
Endochondral
Long bones are initially formed from a cartilage model
Intramembranous
Flat bones are initially formed of connective tissue membranes .

7. Blood supply?
Why?

8. Results in compact bone? Results in spongy bone?

9. Growth of Long Bones Study the picture and then finish the notes.
Figure 6.8

10. Growth: Enlarging Your Bones
Lengthwise growth of long bones occurs in cartilage structures called
epiphyseal plates.
Epiphyseal plates are four-layered structures found between the epiphysis and diaphysis of long bones.
Epiphyseal plates are converted to bone following puberty, ending our ability to increase in height.

11. Is this person done growing?
How do you know?

12. Increasing Bone Diameter.
As your bones lengthen, they must also increase in diameter.
They do this be increasing osteoblast activity in the periosteum.
They must also increase the diameter of their medullary cavity.
They do this by increasing osteoclast activity in the endosteum.

14. Remodeling: Keeping Your Bones New.
Throughout life, we remodel bones to keep them new.
Osteoclasts resorb bone matrix to make room for new matrix.
Osteoprogenitor cells produce new osteoblasts
Osteoblasts produce new bone matrix.
Word bank: Osteoprogenitor, Osteoblast, Osteocyte, Osteoclasts

15. Remodeling
Figure 6.10
Figure 6.9

16. Bone Disease: Osteoporosis
Compare normal bone and osteoporosis.
Collagen framework and deposited minerals are broken down faster than they are formed normally
What happens to the strength of the bone during osteoporosis?
The canals that connect the osteocytes become wider weakening the bone

17. Bone Disease: Sarcoma Bone cancer
Osteosarcoma is the most common and occurs in long bones
Chondrosarcoma occurs mainly in the pelvis, ribs and sternum

18. Osteochondroma
What’s wrong with Curtis?
Non-cancerous bone growth

19. Non-cancerous bone tumor
After removal of a tumor on the femur, a 7 inch incision was made to insert stabilizing hardware.

20. Bone Disease: Osteomyelitis
Infection of a bone, usually by bacteria
Watch Amazing Medical Stories

21. Bone disease: Osteomalacia
What do you notice in the X-ray?
A loss of calcium and phosphorus, often as the result of vitamin D deficiency, can cause weak bones
Known as rickets

22. Bone Fractures Depends on the direction and degree of force. Types
-Simple- bone remains beneath the skin
-Compound- bone projects above skin

23. What type is this?

24. Angular to bone
axis
Twisted
Partial
Right angle
to bone axis
Crushed

25. What’s wrong with Mitch
Transverse fracture

26. Ryan Regeth
What’s wrong?
Broken clavicle at the acromion process

27. Zach Janczak
What’s wrong?
4th metacarpal

28. Alyssa Woo
Stress Fracture: -tiny cracks in a bone -caused by the repetitive application of force, often by overuse -common in track athletes

29. Ms. Cerletty What’s wrong?
Patellar ACL autograft, screw protruding from tibia after 22 years

30. Michael Mathwick
After surgery
Before surgery

31. What’s wrong?
Note the bloody area on the bone. This is where a piece of the femur is missing.

32. Allograft from a cadaver

33. Repaired bone

34. Bone Repair 1 hour Several days 1-2 weeks 2-3 months
Soft, spongy bone is deposited on the callus, blood vessels heal and grow across the break
New compact bone replaces the callus, completing the repair
C. Blood leaking from the site of injury rapidly forms a clot
D. Fibroblasts form a callus. The callus gradually bridges the gap between the broken bone ends, replacing the clot
1 hour
Several days
1-2 weeks
2-3 months