neuromuscular system Flashcards
what is the neuromuscular system
where both the nervous system and the muscles work together to cause movement
sympathetic nervous system
prepares body for exercise
reffered to as flight or fight reponse
parasympathetic nervous system
opposite effect of sympathetic
relaxes body
slows down energy systems
what are the names of the 3 types of muscle fibres
type 1-slow oxidative/slow twitch
type 2a-fast oxidative glycolytic
type 2x-fast glycolytic
type 1-slow twitch/slow oxidative
slow contraction speed
better adapted for low intensity exercises e.g. long distance running
produce energy aerobically (presence of oxygen)
type 2a-fast oxidative glycolytic
more restant to fatigue
used for events e.g 1500m where longer bursts of energy needed
produce energy anaerobically (without presence of oxygen)
type 2x-fast glycolytic
fatigue much quicker than type 2a
used for explosive movements
e.g sprint where fast quick short burst of energy needed
produce energy anaerobically (without presence of oxygen)
characteristics of all three types of muscle fibres
contraction speed
1-slow
2a-fast
2x-fast
myoglobin content
1-high
2a-medium
2x-low
capillary density
1-high
2a-medium
2x-low
mitochondria density
1-high
2a-medium
2x-low
study tip:maddie cant moan
what can training do to muscle fibre
increase the size
what is increasing a muscle called
hypertrophy, where muscle becomes bigger and stronger
what are muscle fibres grouped into
motor units
what does a motor unit consist of
motor neurone and its muscle fibres
only one type of muscle fibre can be found in one particular motor unit
whatt does the motor neurone do
transmits a nerve impulse to the muscle fibre
what is the neuromuscular junction
where the motor neurone and muscle fibre meet
what type of motor units does a fine movement have
only few fibres per motor neurone
what is the all or none law
once motor neurone stimulates muscle fibres, either all of them contract or none of them contract
not possible for motor unit to partially contract
sequence of impulses must be equal to or above threshold, f0r all the muscle fibres in motor unit to contract
fast twitch and slow twitch motor units
brain will recurit slow twich muscle units to low intensity exercises e.g jogging
brain will recurit fast twitch motor units for high intensity exercises e.g 100m sprint
what are the names of the two ways to increase the strength of contraction
wave summation
spatial summation
wave summation
repeated activation of a motor neurone stimulating a given muscle fibre resulting in greater force of contraction
repeated nerve impulse with no time to relax, creating a smooth sustained contraction (tetanic contraction)
spatial summation
when impulses are received at same time at different places on the neurone
recuritment of bigger motor units within a muscle to devlop more force
what does PNF stand for
proprioceptive neuromuscular facilitation
PNF explained
type of advnaced stretching
what are the two proprioreceptors in PNF
muscle spindles
golgi tendon organs
what do muscle spindles do
detect how fast and far a muscle is being stretched
if muscle stretchedd too far, then muscles will contract causing a stretch refex and preventing overstretching
what do golgi tendon organs do
detect tension in muscle
cause muscle t relax overrriding the stretch reflex and causing autogenic inhibition
preventing tearing of muslce
