Neuromuscular system Flashcards
neuromuscular system
- where the nervous system and the muscles work together to allow movement
- changes take place during and after exercise - prepare the bodys
- sympathetic and parasympathatic are part of peropheral nervous system
sympathetic nervous system
prepares the body for exercise and fight or flight response
parasympathtic nervous system
relaxes the body and slows down the high energy functions
muscles fibres
- slow twitch muscle fibres (slow oxidative) - type 1
- fast twitch muscle fibres (as a whole)
- fast twitch type 2a (oxidative glycolytic)
- fast twitch type 2x (glycolytic)
slow twitch muscle fibres (slow oxidative) - type 1
- aerobic exercise
- use oxygen to produce small amounts of tension over long periods
- resistant to fatugue
- endurance athletes have a high percentage
fast twitch muscles fibres
- type 2a and 2x
- anaerobic exercise
- produces larges amount of force in short time
- fatigue easily
- power athletes have a high percentage
fast twitch type 2a - oxidative glycolytic
- fibres most resistant to fatigue
- longer burst of energy
- 1500m runner
fast twitch type 2x - glycolytic
- fibres fatigue much quicker
- high explosive short events
- 100m runner
- quick , short bursts of energy
effects of training on fibre tissues
- hypertrophy
- some become stronger than others
fibre sizes
structual difference - muscle fibres
- slow twitch - small
- fast twitch type 2a - large
- fast twitch type 2x - large
number of mitrochondria
structual difference - muscle fibres
- slow twitch - large
- fast twitch type 2a - moderate
- fast twitch type 2x - small
number of capilaries
structual difference - muscle fibres
- slow twitch - large
- fast twitch type 2a - moderate
- fats twitch type 2x - small
myoglobin content
structual difference - muscle fibres
- slow twitch - high
- fast twitch type 2a - moderate
- fast twitch type 2x - low
pc stores
structual difference - muscle fibres
- slow twitch - low
- fast twitch type 2a - high
- fast twitch type 2x - high
glycogen store
structual difference - muscle fibres
- slow twitch - low
- fast twitch type 2a - high
- fast twitch type 2x - high
triglyceride stores
structual difference - muscle fibres
- slow twitch - high
- fast twitch type 2a - moderate
- fast twitch type 2x - low
speed of contraction
functional difference - muscle fibres
- slow twitch - slow
- fast twitch type 2a - fast
- fast twitch type 2x - fastest
force of contraction
functional difference - muscle fibres
- slow twitch - low
- fast twitch type 2a - high
- fast twitch type 2x - highest
resistance to fatigue
functional difference - muscle fibres
- slow twitch - high
- fast twitch type 2a - low
- fast twitch type 2x - lowest
aerobic capacity
functional difference - muscle fibres
- slow twitch - high
- fast twitch type 2a - low
- fast twitch type 2x - lowest
anaerobic capacity
functional difference - muscle fibres
- slow twitch - low
- fast twitch type 2a - high
- fast twitch type 2x - highest
a motor unit
- muscle fibres are grouped together into motor units
- consists of a motor neuron and its muscles fibres
- motor neurons transmits the nerve impulse to the muscle fibres
- each motor neurone has branches that end in the neuromuscluar junction
slow and fast twitch motor units
- motor units contain the same type of muscle fibres - either fast or slow
- low intensity (jogging) - brain will recruit slow twitch
- strong force of contraction (sprinting) - fats twitch fibres are recruited
the all or none law
- once the motor neuron stimulates the muscle fibres, either all of them contract or none of them do
- threshold - the minimum amount of stimulation required to start a contraction
- if the sequence of impusles is equal to or greater than the threshold - all muscles fibres contract
- if less than - no muscle fibres contract
how to increase/decrease the strength of contraction
- mutiple unit summation
- wave summation
- tetanus/tetanic
- spatial summation
multiple unit summation
how to increase/decrease the strength of contraction
- number of units recruited/more or less
- the strenght of the contraction changed by altering the number and size of muscle fibres - fast twitch instead of slow twitch
- all or none law
wave summation
how to increase/decrease the strength of contraction
- where there is repeated nerve impulse with no time to relax
- smooth, sustained contractions occur rather than twitches
- motor units are unable to relax/increase the force
- tetanic contraction - sustained muscle contractions caused by a series of fast reapeating stimulo
tetanus/tetanic - links to wave summation
how to increase/decrease the strength of contraction
- muscle spindles detect change in muscle length
- sends infomtion to the CNS/brain
- compares infomation to long term memory to ensure correct force is applied
spatial summation
how to increase/decrease the strength of contraction
- by addition of impulses recieved at different places on the neuron
- by sending impulses to different places on the neuron - enables the frequency of impluse
- roating the frequency of the impulse to the motor units to delay fatigue
PNF (proprioceptive neuronmuscular faciliation)
- muscle actions have to be controlled to be effective
- use proprioceptors
proprioceptors characteristics
- infrom the body to what extent of movement has taken place
- muscles spindles
- golgi tendon oragns
muscle spindles
proprioceptors characteristics
- very sensitive - lie between skeletal muscles fibres
- provides excitatory signals to CNS - how far and fast the muscles should stretch
- CNS sends the impulse back to the muscles telling them to contract
- this reflex then causes the muscles to contract to prevent overstretching
golgi tendon organs
proprioceptors characteristics
- found between muscle fibres and tendons
- detect levels of tension in the muscles
- isometrically - detect the increase in muscle tension and sends inhibitory signals to brain
- autogenic inhibitions - allow antagonist muscles to relax and lengthen
