3.2 The autonomic NS and neuromuscular system Flashcards
what is the function of the autonomic nervous system
regulates the function of our internal organs such as the heart
what is the neuromuscular system
the nervous system and the muscles work together to allow movement
what do changes in the neuromuscular system do
they prepare the body for exercise and allow changing demands of different intensities of exercise
what are the types of muscle fibre
- slow oxidative (type I)
- fast oxidative glycolytic (type IIa)
- fast glycolytic (type IIx)
characteristics of slow oxidative muscle fibres
- slower contraction speed
- better adapted to lower intensity exercise
- produce their energy aerobically
characteristics of fast oxidative glycolytic muscles fibres
- more resistant to fatigue
- used for 1500m races for a longer burst of energy
characteristics of fast glycolytic muscle fibres
- fatigue quicker then type IIa
- used for highly explosive events like 100m
differences between fast and slow twitch fibres
is it possible to change muscle fibre
they are genetically determined
- possible to increase the size of muscles fibres - hypertrophy
what is a motor unit
consists of a motor neuron and its muscle fibre - only one type of muscle fibre can be found with a motor unit
what do motor neurones do
transmits the nerve impulse to the muscle fibre - each neuron has branches that end in the neuromuscular junction
what is a neuromuscular junction
where the motor neuron and the muscle fibre meet
what is the all or none law
when a sequence of impulses has to be sufficient intensity to stimulate all of the muscle fibres in a motor unit in order for them to contract
what is wave summation
where there is a repeated nerve impulse without time to relax so a smooth, sustained contraction occurs rather than twitches
what is a tetanic contraction
a sustained muscle contraction caused by a series of fast repeating stimuli
what needs to be released for a muscle to contract
calcium
what is spatial summation
when a strength of a contraction changes by altering the number and size of the muscles motor unitw
what would a wave summation graph look like
what is PNF
an advanced stretching technique
what are muscles spindles
spindles that detect how far and how fast a muscle is being stretched and produce the stretch reflex
what do Golgi tendon organs do
activated when there is tension in a muscle
example of proprioceptors
muscles spindles, Golgi tendons
how do muscle spindles work
send excitatory signals to the central nervous system about how fast and how far a muscle is being stretched
what do Golgi tendon organs do
they sense the increase in muscle tension and send inhibitory signals to the brain which allows the antagonist muscle to relax and lengthen
what is autogenic inhibition
where there is a sudden relaxation of the muscle in response to high tension
how to do PNF
stretch the muscle to 70% then hold for 15s
then see if the performer can be stretched further and repeat the process
