Skeletal system

• Skeleton


  • Provides a framework for movement
  • Made up of bones and joints of different types
  • Provides something for muscles to hold onto
• Skeletal system and muscular system


  Work together to allow movement which occurs at the joints
• Articulating bones


  Bones that meet at a joint to enable movement
• Functions of the skeleton

  • Support
  • Protection
  • Movement
  • Shape and structure
  • Blood cell production
  • Storage of Minerals
• Types of bones


  • Long
  • Short
  • Flat
  • Irregular
• Long bones enable gross movement
• Short bones enable finer controlled movement
• Flat bones are large and protect vital organs
• Irregular bones are specifically shaped to protect
• the skeleton provides a feamework for movement. It is made up of bones and joints of different types which provide something for muscles to hold onto
• joints

  an area of the body where two or more articulating bones meet
• ball and socket joint

  • can move away from the body, back towards the body and rotate
  • eg, shoulder, hip
• hinge joint

  • can only move in one direction, towards and away from eachother
  • like a hinge on a door
  • eg, elbow, knee, ankle
• hinge joint allows flexion and extension
• ball and socket joint allows adduction, abduction and circumduction
• antagonistic pairs

  • the muscle that contracts is the agonist
  • the muscle that relaxes is the antagonist
• antagonistic pairs

  • bicep and tricep
  • gluteals and hip flexor
  • guadriceps and hamstrings
  • tibialis anterior and gastrocnemius
• isotonic contractions


  occur when the muscle changes length when it contracts and results in limb movement
• concentric contractions

  • when the muscle contracts and shortens
  • eg, upwards phase of a bench press/press up
• eccentric contractions

  • when the muscle contracts and lengthens
  • eg, downwards phase of a bicep curl
• isometric contractions

  • occur when the muscle stays the same length
  • the muscles work together to keep the joint stationary
  • eg, plank