1. The framework of our body
Skeletal System
The framework of our body

2. Purpose: 4 Main Functions
Supports the structure of the body
Gives the body shape
Protects vital organs
Serves as attachment for muscles

3. Composition of Skeletal System
Contains 206 bones
Divided into two parts:
Axial Skeleton
Appendicular Skeleton

4. Axial Skeleton Bones that protect vital organs Skull – protects brain
Ribs – protects lungs and heart
Spinal column – houses and protects spinal cord

5. Axial Skeleton

6. Appendicular Skeleton
Appendages – Bones that hang from, or are indirectly attached to axial skeleton
Legs
Pelvis
Arms
Shoulders

7. Appendicular Skeleton

8. Four Main Shapes of Bones
Flat – ribs, shoulder blades
Irregular – vertebrae, tiny ear bones
Short – wrist and ankle
Long – arms, legs, fingers

9. Flat – Ribs

10. Flat – Shoulder Blade (Scapula)

11. Irregular - Vertebrae

12. Short – Wrist and Ankle

13. Long – Arms, Legs, & Fingers

14. Lesson 2: Kinds of Joints
Are meeting points between bones
Control the amount of movement
Are sometimes compared to machines and mechanical gadgets

15. Number and Types of Joints
There are 8 types of joints in the human skeletal system

16. 1. Ball and Socket Allows free movement in all directions
Examples: hips, shoulders, largest knuckles

17. 2. Gliding A.K.A. “Plane Joint” and “Washer Joint”
Limited tilting with pad of cartilage between bone ends
Examples: joints between vertebrae in backbone, wrist, and ankle

18. 3. Hinge
Allows the bones to only move back and forth (no side to side)
Examples: Elbow, knee, smaller knuckles of fingers, toes

19. 4. Pivot Allows rotation, but no other movement
Examples: neck, forearm (ulna/radius)

20. 5. Saddle Allows movement in two directions, but no rotation
Shaped like a saddle for tilting and sliding
Example: Thumb

21. 6. Ellipsoid Allows circular and bending movement but no rotation
Examples: between finger bones

22. 7. Condylar
Similar to hinge but with slight rotation to allow the joint to “lock” into an extended position
Examples: knee

23. 8. Fixed or Suture Joint
Allows no movement at all because the bones are firmly joined together
Examples: Between bones of cranium around brain