Skeletal system

• Structure of the skeleton:

  Skeletal system allows movement at a joint.

  The shape and type of the bones determine the amount of movement - short bones enable finer controlled movements, long bones enable gross movement.

  Flat bones protect vital organs.

  Different joint types allow different types of movement.

  Provides a point of attachment for muscles - when muscles contract they pull the bone.
• Functions of the skeleton: Support


  Bones are solid and rigid. They keep us upright and hold the rest of the body - the muscles and organs - in place
• Functions of the skeleton: protection 


  Parts of the skeleton protect the body’s organs from external forces, e.g. brain is inside the cranium, ribs protect the heart and lungs.
• Functions of the skeleton: Movement

  The skeleton helps the body move by providing anchor points for the muscles to pull against.

  Long bones in the arms and legs work as levers to allow certain movements.
• Functions of the skeleton: Structural shape


  The skeleton gives us our general shape such as height and build. 

  • Tall people have long leg bones and larger vertebrae.
  • People with a heavy build have larger clavicles and scapula as well as bigger pelvises.
  • The skeleton provides a frame for muscles to attach to.
• Functions of the skeleton: Mineral storage


  Bones can store several minerals, including calcium and phosphorus, which can be released into the blood when needed.
• Functions of the skeleton: Blood cell production


  The inner marrow of the long bones and ribs produces red and white blood cells.
• Long Bones

  Support body weight and help with gross movements.
• Short bones 


  Used in fine, delicate movements of the body.
• What is a joint?

  Where two or more bones meet/are attached for the purpose of motion of body parts.
• Ball and socket joints 


  Allow movement in all directions. These are the most mobile joints in the body. As a result they are more likely to dislocate than other less mobile joints
• Hinge joints


  Only allow flexion & extension.
• The body has 3 different types of joint, each offers different amounts of movement. They are called immovable, slightly movable or freely movable joints. These are examples of freely movable (synovial) joints.
• Rotation


  Turning a limb along its axis
• Extension


  Increasing the angle at a joint.
• Abduction


  Movement of limbs away from the centre of the body.
• Adduction


  Movement of limbs towards the centre of the body.
• Circumduction


  Cone like movement of a body part, a combination of flexion, extension, abduction and adduction.
• Flexion


  Decreasing the angle at a joint.
• Dorsiflexion


  Action of pulling toes towards your knee.
• Plantar flexion


  Action of pointing toes towards the ground.
• What is the difference between ligaments and tendons?

  Ligaments joins bones to bones and tendons join muscle to bone.
• Which type of synovial joint allows the greatest range of movement?

  Ball and socket