SKELETONS AND JOINTS

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SKELETONS AND JOINTS
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FUNCTIONS

• SHAPE AND SUPPORT provides a frame
• MOVEMENT occurs where bones meet
• PROTECTION surrounds vital organs
• BLOOD PRODUCTION made in bone marrow

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FUNCTION - SHAPE AND SUPPORT

• Provides a framework to support all organs,
  muscles and other components of the body
• Determines shape and size of the body e.g. taller
  people have longer bones

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FUNCTION - MOVEMENT

• Where 2 bones meet is called a JOINT.
• Movement occurs at the joint when muscles on
  either bone that meets at the joint contracts.
• This is called ARTICULATION
• The joints with the greatest range of movement
  are the shoulder, elbow and wrist, and the hip,
  knee and ankle.

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FUNCTION - PROTECTION

• The skeleton provides a protective cage around
  vital organs of the body.
• The ribs protect the heart and lungs.
• The skull protects the brain.
• The pelvis protects the abdomen.
• The vertebral column protects the spinal chord.

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FUNCTION - BLOOD PRODUCTION

• Blood contains both red and white blood cells.
• Red cells carry oxygen to the muscles.
• White cells fight infection in the body.
• Blood cells are produced in the BONE MARROW
  inside the long bones of the body.

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TYPES OF BONE

• There are 3 main types of bone.
• LONG found in the arms and legs. They are the
  levers of the body where a lot of movement
  happens e.g. humerus, radius, ulna etc.
• FLAT plate-like bones that have a large surface
  area for protective purposes e.g. cranium,
  scapula, pelvis etc.
• IRREGULAR serves a protective function e.g. the
  vertebrae protect the spinal chord.

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BONES AND MOVEMENT

• OVERHEAD CLEAR IN BADMINTON
• Long bones (humerus, radius, ulna, phalanges and
  metacarpals).
• Flat bones (scapula, clavicle).
• Irregular bones (carpals).
• What bones are involved in a golf swing, throwing
  a javelin, and kicking a ball?

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SYNOVIAL JOINTS

• Synovial joints are enclosed within a synovial
  capsule.
• Synovial fluid lubricates the joint for smooth
  movement.
• Cartilage covers the end of the bones in the
  joint and acts as a shock absorber.
• Ligaments attach bone to bone and provide
  stability at the joint.
• Tendons attach muscle to bone.

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SYNOVIAL JOINTS
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PROPERTIES OF CARTILAGE, LIGAMENTS AND TENDONS

• Smooth and tough
• Slightly flexible (for impact)
• No blood vessels
• Shock absorber between bones
• Prevents bones from wearing away by rubbing
  against each other

• Tough
• Non-elastic
• Many fibres
• Attaches muscle to bone
• Transfers force from muscle to bone, creating
  movement

• Tough and flexible
• Connects 2 bones together
• Prevents easy dislocation (stabilises the joint)
• Restricts excessive movement

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TYPES OF MOVEMENT

• FLEXION - reducing the angle between 2 bones at
  a joint
• e.g. bending at the elbow in a bicep curl

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TYPES OF MOVEMENT

• EXTENSION increasing the angle (straightening)
  between 2 bones at a joint
• e.g. straightening the knee to kick a ball

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TYPES OF MOVEMENT

• ROTATION movement around an axis point
  (swivelling)
• e.g. turning your head to the side to breath
  when swimming

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TYPES OF MOVEMENT

• ABDUCTION taking a limb away from the central
  body line
• e.g. an outwards kick in karate

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TYPES OF MOVEMENT

• ADDUCTION taking a limb towards the central
  body line (across the body)
• e.g. a left hook in boxing

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TYPES OF SYNOVIAL JOINT

• BALL AND SOCKET one end of a bone is rounded
  (like a ball) and fits into a hollow socket at
  the end of the other bone.
• Where? shoulder (clavicle and humerus) and hip
  (pelvis and femur).
• Movement rotation, flexion and extension,
  adduction and abduction (greatest range of
  movement).
• e.g. bowling in cricket,
• overhead clear in
• badminton.

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TYPES OF SYNOVIAL JOINT

• HINGE 2 bones meet at either end and are
  connected by ligaments to stop dislocation.
• Where? knee (femur and tibia/fibula) and elbow
  (humerus and radius/ulna).
• Movement flexion and extension only.
• e.g. kicking a ball
• bicep curl
• press-ups.

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TYPES OF SYNOVIAL JOINT

• GLIDING small bones move over one another to
  allow flexibility.
• Where? hands (carpals/metacarpals) and feet
  (tarsals/metatarsals).
• Movement flexion and extension through hands
  and feet
• e.g. pointing toes in gymnastics.

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TYPES OF SYNOVIAL JOINT

• PIVOT the end of 1 bone has a peg that fits
  into a ring formed by the other bone.
• Where? cranium and spinal column (neck).
• Movement rotation.
• e.g. turning head to the side to breath
  in swimming.