1. SKELETAL SYSTEM Section 1

2. WARM-UP Answer the following questions to the best of your ability…. 1. How many bones are in the human body? Does that number ever change? 2. Why do we have bones? 3. Are bones alive? 4. What makes up your Skeletal System?

3. Skeletal System  Made up of all the bones and cartilage in your body  Has 5 major functions:  Gives shape and support to your body  Protect internal organs  Major muscles are attached to your bones  Blood cells are formed in the marrow of your bones (center)  Calcium and Phosphorus compounds are stored in your bones for later use

4. DISCOVERY EDUCATION

5. Bone Structure PERIOSTEUM COMPACT BONE SPONGY BONE

6. CARTILAGE  Acts as a SHOCK ABSORBER  REDUCES FRICTION between bones when they rub together  NO CARTILAGE= PAIN!!!

7.  Before birth, your Skeletal system was ALL CARTILAGE  It gradually is replaced by bone…the Skeletal System you were born with

8.  Osteoblasts- Build bone with Calcium and Phosphorus, which make it hard  Osteoclasts-Break down bone tissue  If you don’t use it, you loose it!!!

9. Joints  Any place where two bones come together

10. Types of Movable Joints

11. Pivot Joint  One bone rotates in a ring of a stationary bone  Ex. Turning your head

12. Ball and Socket Joint  The rounded end of one bone fits into a cuplike cavity on another bone  Ex. Shoulder/hip

13. Hinge Joint  Back-and-forth movement  Ex. Elbows, Knees, Fingers

14. Gliding Joint  One part of the bone slides over another one  Ex. Wrists, Ankles, Between Vertebrae  Used the MOST in the body

15. IMMOVABLE JOINTS  Allow little to NO movement  Ex. The joints of the bones in your skull, pelvis, and vertebrae

16.  5 gliding

17. How many bones are in the human body? 206 Does that number ever change? YES

18. Why do we have bones?  Gives shape and support to your body  Protect internal organs  Major muscles are attached to your bones  Blood cells are formed in the marrow of your bones (center)  Calcium and Phosphorus compounds are stored in your bones for later use

19. Are bones alive? YES

20. What makes up your Skeletal System? Bones and Cartilage