1. Skeletal System Notes

2. Your body has two organ systems that work together to provide support & help you move– the skeletal system & the muscular system.

3. The skeletal system is made up of bones & cartilage that form the framework of your body.

4. The muscular system includes the muscles that help you move & help things inside your body move.

5. All humans have a stiff internal skeleton made of bone.

6. The bones of your body have five main jobs–

7. -to support the body & give it shape

8. -to protect internal organs
-to work with the muscles to move
-to protect internal organs

9. -to store fat & other minerals (calcium & phosphorus)

10. -to make blood cells (bone marrow)

11. A human baby is born with 350 bones, but an adult human has 206 bones.

12. Bones are made up of mostly calcium & phosphorus.

13. Bones are very much alive & contain blood vessels & nerve tissue.

15. Cartilage is a strong flexible connective tissue found at end of bones where it acts as a cushion.

16. Cartilage has no blood cells so it must absorb nutrients from body fluids. (diffusion)

17. Bones are attached to other bones by connective tissues called ligaments.

18. A joint is the place where two bones come together & are joined by ligaments to allow bones to move in different ways.

19. Two types of joints in the body…

20. Immovable joints allow little or no movement (skull & ribs)

21. Movable joints that allow a wide range of movement.

22. Bones rotate around each other (allows side-to-side motion)
Pivot joint
Bones rotate around each other (allows side-to-side motion)

23. Examples…
Neck

24. Bones slide over each other (allows you to bend & flex)
Gliding joint
Bones slide over each other (allows you to bend & flex)

25. Examples…
Wrist, ankle, vertebrae (back)

26. Back-and-forth motion (can only move one direction… unable to twist)
Hinge joint
Back-and-forth motion (can only move one direction… unable to twist)

27. Examples…
Knee, elbow, fingers, toes, jaw

28. Rotational or circular motion… greatest range of motion
Ball & socket joint
Rotational or circular motion… greatest range of motion

29. Examples…
Shoulder, hip

30. The best ways to keep your bones healthy are regular exercise & to eat a balanced diet with meats, beans, green leafy vegetables & dairy products.

31. Osteoporosis is the condition where mineral loss can cause bones to become weak & break easily.