neuromuscular system Flashcards
autonomic
regulates the function of internal organs
works involuntarily
neuromuscular
where the nervous system and muscles work together to produce movement
central nervous system and peripheral nervous system
central nervous system
spinal cord and brain
peripheral nervous system
everything that come of the cns
sympathetic
flight response
prepares the body for exercise
parasympathetic
relaxes the body and slows down energy functions
relax and rest
type 1 slow oxidative
lots of mitochondria and myoglobin
fatigue resistant
for low intensity and long duration
endurance events
dominant at rest
red in colour
slower o contract and slower to tire
resynthesise atp using oxygen
type 2a fast oxidative glycolitic
pink in colour
adapt specifically to different types of training to behave more like type 1 or type 2b
can produce energy through anaerobic and aerobic processes
some mitochondria giving them a fast recovery and fatigue resistant aspect
1500m runner
type 2b fast glycolytic
white in colour
produce quick bursts of speed
power lifting and sprinting
used in short bursts, high intensity and explosive movements
fastest contraction and quickest to fatigue
low oxidative capacity and low in mitochondria
effects of training
what muscle fibre you have is genetically determined
you can increase the size of fibres through training
this is called hypertrophy
motor unit
muscle fibres are grouped into motor units consist of motor neuron and its muscle fibres
Only one type of muscle fibre can be found in one particular motor unit
Muscle fibres work with the nervous system so that a contraction can occur
The motor neuron transmits nerve impulses to the muscle fibre
Each motor neuron has branches that end in the neuromuscular junction on the muscle fibre
Each muscle is made up of many major units and they’re very in size
A small muscle that is used for fine motor control will have motor units that only have a few fibres per motor neuron
A large muscle that is used for gross motor control will have motor units with a motor neuron feeding hundreds of fibres
all or none law
once the motor neurone stimulates the muscle fibres either get all of them contract or none of them contract
Motor unit can’t partially contract
Minimum amount of stimulation needed to start contraction
If the sequence of impulses is equal to or more than threshold all the muscle fibres in motor units will contract
However, if the sequence of impulses is smaller than the threshold, no muscle action will occur
how to increase force of contraction
wave summation
spatial summation
wave summation
repeated activation of a motor neuron stimulating a given muscle fibre results in a great force of contraction
Each time the nerve impulse reaches the muscle cell calcium is released
If there are repeated nerve impulses with no time to relax, calcium will build up. This produces a forceful sustained smooth contraction known as a tetanic contraction.
spatial summation
The recruitment of additional and bigger motor units in a muscle to develop more force
Impulses are received at the same time at different places on their neuron which add up to fire the neuron
In order to delay fatigue, you can rotate the use of motor units through spatial summation
motor unit
A motor neurone and its muscle fibres
motor neurones
nerve cells which transmit the brains instructions as electrical impulses too muscles
neuromuscular junction
where the motor neurone and muscle fibre meet
all or none law
where a sequence of impulses has to be a sufficient intensity to stimulate all muscle fibres in a motor unit for them to contract
muscle spindles
Detect how far and how fast a muscle is being stretched and produces the stretch reflex
autogenic inhibition
sudden relaxation of the muscle in response to high tension
involves golgi tendon organs
proprioreceptive neuromuscular facilitation
advanced stretching technique
one of the most effective forms of flexibility training for increasing range of motion
there are a few different techniques but the most practical is the CRAC technique
CRAC technique
1 passive stretch
athlete on the floor, coach pushing leg to stretch hamstring
2 contract against resistance
isometric contraction
athlete pushes against the coach
3 relax passive stretch
athlete then relaxes and coach pushes athletes leg further
muscle spindles
lie between muscle fibres
provide the CNS with info about how fast and far a muscle is being stretched known as excitory signals
the CNS sends an impulse back to the muscle telling it to contract which triggers the stretch reflex
this reflex action that causes the muscle to contract to prevent overstretching and reduces the risk of injury
golgi tendon organs
between muscle fibre and tendon
detect levels of tension in a muscle
when the muscle is contracted isometrically in PNF they sense the increase in muscle tension and send inhibitory signals to the brain which allows the antagonist muscles to relax and lengthen
evaluation of PNF
most effective way of increasing flexibility
improves performance in aesthetic sports
less likely to be injured during a game or training
need a professional to do the stretching
power athlete would not use this as it reduces power in the short term
increased risk of injury
