Skeletal System

1. Skeletal System Structure of Bone

2. What are bones? • Why does milk do a body good? • Which do you think is a better model of bone. A stick of chalk or a piece of sponge?

3. Functions of the Skeleton • Provides attachment for skeletal muscles and supports softer tissues • Store and • Produces • Storage of

4. Bone Cells Breaks down bone Maintains cellular activities of bone Create bone

5. Structure of Bone • -a tough layer of connective tissue surrounding bone on outside

6. Structure of Compact Bone Cont. • _____________ bone is a thick layer found just inside the periosteum that runs the entire length of bone • Made up of structural units called ___________ which consist of _______________, many hollow tubes of bone matrix that function as tiny weight bearing pillars • Resemble

8. Compact Bone Structure Where lamellae meet there are spider shaped _______________ in lacunae (small holes) which help ______________________________

9. Structure of Compact Bone Cont. • _______________ Canal • Runs through • Contains Central canal

10. Central canal

11. Spongy Bone • Found • Found in the ends of ___________________and in the middle part of short, flat bones • Made up of ___________________ which is a meshwork of bony bars that gives strength to the bone without adding mass • NO • Red bone marrow found in the spaces between trabeculae and makes

12. Compact bone Spongy Bone

14. Bone Remodeling • Bone resorption • __________________ break down bone matrix by forming grooves or pits and secreting enzymes and acids to digest the matrix and turn calcium salts into soluble forms • _____________________or build-up happens where bone is injured or where added bone strength is needed

15. Bone Growth-Ossification • Grows in length in long bones at either end in regions know as • ________________ cells in this area divide and increase in number pushing older, larger cartilage cells toward the middle of the bone causing growth • The older cartilage cells die and the space the occupied is replaced with bone • At the end of puberty, the growth plate is replaced with bone and the person stop getting taller

16. Living vs. Non-living Components • Living parts • Non-living Parts

17. Effect of Exercise on Bone • Bones grow in thickness due to • ____________ must be placed on bones for ossification to occur because this force is what stimulates the _______________ to secrete the minerals that replace cartilage • What do you think might happen to bones that are not exposed to force, such as bones of astronauts in zero gravity?

18. Broken Bone • How does broken bone heal? • Step 1: ______________forms at fracture site and bone cells deprived of nutrients soon die while tissue becomes swollen, painful and inflamed • Step 2: ____________________________forms splinting the broken bone • Step 3: callus is converted into ________________________________; begins 3-4 weeks after injury and continues until firm union about 2-3 months later • Step 4: _________________________________; compact bone reforms shaft walls and ______________________ remove unnecessary materials

20. Osteoporosis • Bone mass is reduced making bone • Occurs most often in _________________________________________due to a decrease in production of __________________ which normally restrains osteoclasts and promotes deposit of new bone • Prevention: • Treatments

22. Bone Videos • http://dsc.discovery.com/videos/human-body-strength-tornado-boy.html • http://dsc.discovery.com/videos/human-body-strength-street-gymnast.html • http://investigation.discovery.com/videos/the-real-ncis-bones.html