The Functions of the skeleton
Think: Sport Makes Perfect
- Gives us our posture and shape
- Without it, we would collapse.
- Muscles attached to bones by tendons allow movement.
- Different types of movement at different types of joints.
- Protects the vital organs (heart and lungs protected by ribs).
- Protects our organs during sport (rugby scrum, boxing).
Movements that different joints allow
Think: After Exercise Always Rest Feet
Abduction - Moving away from an imaginary centre line (Think: Abducted by aliens)
Extention - Straightening/Extending a joint. (Think: Straight line 180 degrees)
Adduction - Moving towards an imaginary centre line (Think: Adding something to yourself)
Rotation - A turning movement around a central point.
Flexion - Bending/Flexing a joint. (Think: L shape 90 degrees)
Different Types of joint
Think: Sport Is Fantastic
Slightly moveable joints:
- Movement is needed here, but only to a certain point (e.g. the vertebral column).
Immovable (fixed) joints:
- Movement would be a disadvantage here (cranium).
- Joints are held by very tough tissues which develop from childhood.
Freely moveable joints: (or synovial joints)
- Reasonable degree of movement occurs.
- Surrounded by a capsule which secrets synovial fluids, allowing them to move differently.
The different synovial joints
Think: George Best Couldn't Help Sink Pints
Gliding joint - (Small bones of hands and feet) Allows a small amount of each movement. (Catching a ball).
Ball and Socket joint - (Shoulder, Hip) Allows all the different types of movement. (Kicking in karate) (Arm action in front crawl in swimming).
Condyloid joint - (Wrist) Allows Flexion, Extension, Adduction and Abduction. (Backhand lift in badminton).
Hinge joint - (Knee, Elbow) Allows Flexion and Extension. (Kicking a football) (Breaststroke arm action in swimming).
Saddle joint - (Thumb) Allows Flexion, Extension, Adduction and Abduction. (Switching grips quickly in badminton).
Pivot joint - (Neck) - "Atlas and Axis" - Allows rotation. (Heading a ball in football).
The different connective tissues
- A soft cushion in a joint.
- Stops 2 bones rubbing together
- Like very strong string
- Attaches bone to bone
- Stops bones going out of place and overstreching
- White flexible cords, or straps
- Attach muscle to bone (or to other muscles)
Long Term Effects on the Skeletal System
Bone Density Increases - if bones become more dense, they increase in strength, preventing injuries, such as fractures and osteoporosis.
Ligaments + Tendons become more flexible/stretchier - if ligaments and tendons become more flexible/stretchier, you can train harder without injuring yourself. This will also prevent injuries, such as inflammation, and sprains.
Osteoporosis (brittle bones)
- It can be developed as an inherited disease, or as an individual becomes older (when bones lose their density).
You prevent this by eating food rich in Calcium (dairy products) and Vitamin D (Vegetables and fruit), or participate in weight bearing exercises (anything where your feet make contact with the ground).