1. Growth

2. Identify 3 types of bone cells 1. 2. 3.

3. 3 types of bone cells Osteocytes (osteons) – mature bone cells, in both spongy and compact bone Osteoclasts- multinucleated & dissolve bone matrix Osteoblasts- build new cells

4. Osteons Structures Functions Location Parallel to long axis of bone Therefore, limb does not bend Stress from one direction

5. Composition of bones Compact Spongy Epiphyseal line/plate

6. What is the main difference between spongy and compact bone? Why is a fracture more likely from the side of a bone? What does the presence of an epiphyseal line mean?

7. Bones If collagen increases in a bone, how is the strength of the bone affected? What is the anatomical and thus physiological difference between the diaphysis and epiphysis ? If osteoclast activity is higher than osteoblast activity what happens to a bone?

8. Calcification / ossification

9. Calcification vs. Ossification Calcification Buildup of Ca Occurs during ossification Can also occur in joints or other ares Ossificiation Intramembranous – bone develops directly Endochondral – bone replaces catilage Epiphyseal cartilage - at ends of epiphysis reduces as growth slows

10. What affects the growth of bones?

11. Why do teens grow suddenly? What happens at puberty? Is exercise important to bone development? How?

12. Primary/Secondary growth Elongation –diaphysis growth Laterally- the periosteum is increasing in osteoblasts, towards the inside, ________ are __________ and marrow cavity is increasing

13. When does one stop osteoblasting? Skull Toes Long bones Pelvis

14. What is needed for bone growth? Vitamins and minerals Sex hormones Fractures – will they stop growth? Stress applied to bones- good or bad? Why?

15. Vitamins A C D

16. Minerals Ca P

17. Age Normal loss of bone due to aging= osteopeniaj Hormone levels change Reduction in osteoblast activity Bones become ----? Who is affected more? Men/women Is this equally affecting the entire body or are some areas more affected earlier? What helps to reduce this process? Disorders/ diseases

18. What type of tissue is replaced by bone during intramembranous ossification? How would an X-ray of a femur tell if a person had stopped growing? Why should a pregnant woman take vitamin and mineral supplements?