1. Bone Growth

2. How is bone formed in a growing infant? • Calcified bone matrix replaces the cartilage. • The bone is remodeled. • The cartilage bone serves as a mold

3. Bone Development in a Newborn

4. Bone Remodeling

5. What roll do osteoblasts and osteoclasts have in bone formation? • Osteoblasts = bone-forming cells • These cells form the cells needed to form a bone • Osteoclasts = bone-resorbing cells • These cells absorb the important nutrients needed to form bone

6. What hardens a bone? • The laying down of calcium salts in the matrix

7. Why is it that athletes have stronger denser bones than non-athletes? • Stresses on bones during exercise increases the rate of bone deposition

8. What do all bones start out as? • Cartilage models • Infants have such soft skeletons • Infants and toddlers are extremely flexible. • Their skull has not fully ossified yet • Soft spot

9. What is the process of endochondral ossification and which direction does it occur? • Bone is formed inside a cartilage “mold” • The process is ossification. • Bone grows inside out and at the ends. • Blood vessels penetrate the cartilage model to provide nutrients to the Osteoblasts & Osteoclasts to sustain their growth & function

10. A • Catilage Mold • B • Blood vessels invade Diaphysis • Osteoblast and Osteoclast action • Medullary Cavity forms • Calcification • Bone Tissue

11. C • Continuing of Osteoblast and Osteoclast action • Medullary Cavity more defined • Greater Calcification • D • Epiphyseal calcification begining

12. E • Ossification continues in the epiphysis • F • Growth Plate appears showing dividing the Epiphysis and Diaphysis • G • Growth Complete, Growth plate calcified

13. When does bone growth cease? • When all the epiphyseal cartilage is converted into bone. • The growth plate closes

14. What roll does the growth plate (epiphyseal plate) have in bone growth? • The diaphysis grows towards the epiphysis at the plate. • When the growth plate is still visible, growth is still occurring • The Diaphysis and Epiphysis haven’t fused

15. Spinal Cord

16. How many curves do you have in your spine? Where are the convex curves? Where are the concave curves? • 4 • Concave • Cervical / Lumbar • Convex • Thoracic / Sacral

17. How is an infants spine different from an adult? • In infants, the spine is a continuous convex curve. • As they develop muscle strength to hold their head up, the concave curve develops at the neck. • As they learn to stand and strengthen their legs and abdomen, they get a convex curve in the lumbar region

18. What function to these curves have in your spine? • Strength to support the weight of the body • Balance for standing and locomotion • Curves re-disdribute the forces of gravity and stress