GCSE PE UNIT 1 - muscles of the body

• Muscles attach to bones via tendons to allow movement at

  joints.
• The muscular system is made up of over 600 muscles
• Primary purpose of the muscular system

  To provide movement for the body
• Muscular system properties

  • Excitable/irritable
  • Contractable
  • Extensible
  • Elastic
  • Adaptable
• Muscle contraction


  1. Receive stimulation from nerves

  2. Contract/shorten
• Muscle extensibility


  Can be stretched without damage by application of force
• Muscle elasticity


  Able to return to original resting shape and length after being extended or contracted
• Muscle adaptability


  Can be changed in response to how it is used (e.g. enlarge with increased work, atrophy with lack of work)
• Types of muscle movements

  • Adduction
  • Abduction
  • Flexion
  • Extension
  • Rotation
• Types of muscles

  • Cardiac (involuntary)
  • Visceral/smooth (involuntary)
  • Skeletal (voluntary)
• Skeletal muscles attach to the skeleton and provide the ability to move
• Tendons

  Attach muscles to bones
• Fascia


  Connects muscles to other muscles
• The nervous system is intrinsically connected to the muscular system and is essential for voluntary skeletal muscle movement
• If communication from the nervous system is severed from skeletal muscles, the body will be in a state of paralysis (quadriplegic)
• The only organ not directly dependent on the nervous system is the cardiac/heart muscle
• Muscles work in pairs, these are called antagonistic

  pairs.

  As one muscle contracts (agonist/prime mover), the

  other (antagonist) relaxes.
• Isotonic = muscle changes shape:

  A – Concentric contractions = when the muscle shortens (i.e. bicep shortens when

  the elbow bends).

  B – Eccentric contraction = when the muscle gradually lengthens & returns to its

  normal length & shape (i.e. Bicep muscle undergoes eccentric contraction when

  the arm straightens back up after it has been bent).

  Isometric contraction

  NO actual movement of a limb or a joint so the length of the muscle is not affected.

  Muscles are working although they are stationary!

  i.e. Gymnast holding a handstand = isometric contraction in the arm muscles.