Functional Anatomy

• what surrounds the muscle belly

  epimysium
• muscle belly is made of of bundles of

  fascicles
• fascicles are surrounded by

  permysium
• each fascicle contains individual muscle fibres surrounded by

  endomysium
• each fibre is arranged into

  myofibril
• myofibrils contain a chain of sacromeres composed of

  actin and myosin
• During Eccentric Contraction

  Everything Increase except for A-band which stays the same
• During concentric Contraction

  Everything Decreases except for A-band which stays the same
•  sensory neurons send messages to the brain via spinal cord
• The 2 components of the peripheral nervous system

  • the sensory division
  • the motor divison
• motor unit is

  The motor neuron and all the fibres in innervates
• All or None Principle

  When a motor unit receives action potential that exceeds the neural threshold, all the muscle fibres associated with it will contract to their maximum potential
• Type I characteristics

  • slow contraction speed
  • low force production
  • high resistance to fatigue
  • aerobic
• Type II A characteristics

  • fast contraction speed
  • high force production
  • medium resistance to fatigue
  • long term anaerobic
• Type II B characteristics

  • Very fast contraction speed
  • Very high force production
  • low resistance to fatigue
  • short term anaerobic
• Force velocity

  Describes the relationship between the amount of force produced by a muscle and the velocity of movement/muscle contraction.
• Force length

  Relates to the amount of muscle force that can be produced at varying muscle lengths
• Types of Muscle Contraction

  • concentric
  • Eccentric
  • isometric
• Concentric Contraction

  when movement is in the opposite direction to the gravitational pull
• Eccentric Contraction

  when movement is in the same direction as the gravitational pull
• Isometric Contraction

  muscle contracts, but no movement occurs
• Origin


  the attachment of the bone that does not move when the muscle contracts
• Insertion


  attached to the bone which moves when the muscle contracts