Neuromuscular system

• What does the CNS stand for

  Central Nervous System
• what is motor unit

  the motor neurone and the muscle fibres it stimulates
• how do skeletal muscles contract

  via an electrical impulse
• what is the sympathetic nervous system

  "fight or flight response"

  readies the body for exercise
• what is the parasympathetic nervous system

  relaxes the body, returns body to pre-exercise state, reduces high energy functions
• what do motor neurones do

  conduct nerve impulses rapidly to a group of muscle fibres
• what is action potential

  positive electrical charge inside the nerve and muscles cells which conducts the nerve impulse down the neuron and into the muscle fibres
• what is the neuromuscular junction

  the point the axons motor end plates meet the muscle fibre
• what if the synaptic cleft

  small gap between the motor end plates and the muscle fibre
• an action potential cannot cross the synaptic cleft without a neurotransmitter called what

  acetylcholine
• what is the all-or-none law

  all muscle fibres contract at the same time with maximum force
• can muscles fibres partially contract


  no
• what is released which creates a wave of muscular contraction down the muscle fibre

  calcium
• what is spatial summation

  this is when we can change the strength of contraction by altering the number of motor neurones we recruit
• what is wave summation

  repeated activation of a motor neurone stimulating a muscle causes greater force of contraction
• what is tetanic contraction

  sustained and powerful muscle contraction caused by a series of fast, repeating stimuli
• what is the order of muscular contraction

  1. muscle impulse initiated in the motor neurone cell body
  2. nerve impulse conducted down axon of the motor neurone to the muscle fibres
  3. muscle contracts in 'all-or-none' fashion
  4. if the electrical charge is above threshold and enough acetylcholine is present, the muscle fibres will contract
• What are the 3 types of muscles fibres

  Slow oxidative

  Fast oxidative glycolytic

  Fat glycolytic
• what are some features of the Slow oxidative muscle fibre

  Have slow contraction speed

  aerobic better for low intensity exercises (marathon running)
• What are features of fast twitch muscle fibres

  fast contraction speed

  fatigue very quickly

  used for short, intense burst of energy

  produce energy aerobically
• What are features of Fast oxidative glycolytic muscle fibres

  more resistant to fatigue

  used for events like 1500m in athletics

  long burst of energy is required
• What are some features of fast glycolytic muscle fibres

  fatigue much quicker

  high explosive events

  100m in athletics

  short quick burst of energy
• How can you increase the size of muscles fibres

  hypertrophy
• What does PNF stand for

  Proprioceptive neuromuscular facilitation
• What is PNF 


  advanced stretching method
• Does PNF assist flexibility training 


  YES
• What are two types of proprioceptors

  Golgi tendon organs

  Muscle spindles
• What are muscle spindles

  These detect how far and fast a muscle is being stretched and produce the stretch reflex
• What are Golgi tendon organs

  activated when there is tension in the muscle
• what is an isometric contraction

  where there is visible tension in a muscle but no visible movement
• What is autogenic inhibition

  where there is a sudden relaxtion of the muscle in response to high tension

  receptors involved in the process are the golgi tendon organs