1. The Skeleton and Muscles

2. Why Do We Need A Skeleton?
It supports our body (creates room for the lungs etc.)
It allows us to move
Protects vital organs
Why is the skull so thick?
To protect the brain
Why do we need ribs?
To protect the lungs and heart

3. The Skeleton There are about 206 bones in the average human body
Babies are born with 300 bones

4. Joints Joints are places where two bones join They allow movement
Cartilage and synovial fluid prevent bones wearing away

5. Parts Of The Joint Ligaments: Hold two bones together at a joint
Cartilage: Connective tissue that prevents two bones from wearing each other out
No cartilage or synovial fluid is a cause of arthritis
Tendons: Holds muscle to bone

6. Types Of Joints Ball and socket e.g. hip and shoulder
Allow lots of movement

7. Types Of Joints Hinge e.g. knee, elbow etc.
Allow forward and backward movement, but no sideways movement

8. Types Of Joints Saddle e.g. fingers Allow us to grasp things

9. Types Of Joints Fixed Joints e.g. the bone in the skull
These joints do not move

10. Types Of Joints Slightly moveable joints e.g. the vertebrae
Allow limited movement

11. Movement
Bones cannot move on their own
They are pulled by muscles

12. Muscles Muscles cannot push, they can only pull when they contract
How do we push doors closed?
Muscles work in antagonistic pairs, the bicep pulls the forearm up to the upper arm, the triceps straightens the arms. We use the triceps to close a door

13. Antagonistic Pairs The bicep flexes the arms
The triceps extend the arm

14. Muscles In The Body
There are about 650 muscles in the human body

15. Types Of Muscle There are three types:
Cardiac muscle: beats on it’s own, never rests
Involuntary muscle: this muscle works without us thinking about it e.g. breathing, peristalsis, pupil dilation
Voluntary muscle: we have to think about moving these muscles e.g. skeletal muscles