neuromuscular system Flashcards
slow twitch muscle fibres are also known as
type 1 muscle fibres
type 2 a are also known as
fast oxidative glycolytic fibres
type 2 b are also known as
fast glycolytic
what are the 6/7 things to remember when describing muscles fibres
how fast they contract
aerobic or anaerobic
blood cells and colour
myoglobin+ mitochondria levels
fatigue?
sporting examples
type 1- slow twitch muscle fibres characteristics
contract slowly
produce small power
do not fatigue quickly
aerobically powered
high rbc content that carries o2
high myoglobin + mitochondria
long dist, endurance events eg walking and marathon
type 2a - fast twitch
contract quickly and with power- mid
anaerobically powered but do use small percentage of oxygen
fatigue fairly quickly
limited red blood cells and appear pink
fewer myoglobin and mitochondria than type 1
quick events that involve prolonging power, speed and explosive qualities (1-2 mins) eg 400m and 800m running
type 2b - fast twitch
contract the quickest and with the most power
powered anaerobically
have minimal o2 supply and use ATP/PC energy system
they are white as they have few to zero rbcs
have no myoglobin and mitochondria
fatigue very quickly
fast explosive events 100m sprint, shot, discus
major storage fuel for type 1 fibres
triglycerides
major storage fuel for type 2a
glycogen
major storage fuel for type 2b
PC
myosin ATPase levels for type 1
low
myosin ATPase for type 2a
intermediate
myosin ATPase for type 2b
high
glycogen stores for type 2a
high
glycogen stores for type 1
low
glycolytic capacity for type 1
low
glycogen stores for type 2b
very high
glycolytic capacity for type 2a
high
glycolytic capacity for type 2b
very high
capillary density for type 1
high
capillary density for type 2a
intermediate
capillary density for type 2b
low
muscle fibre diameter for type 1
small
muscle fibre density for type 2a
intermediate
muscle fibre density for type 2b
very large
size of motor neurone for type 2b
large
size of motor neurone for type 1
small
size of motor neurone for type 2a
large
activity type for type 1
aerobic
activity type for type 2b
short anaerobic
activity type for type 2a
longer anaerobic
what benefit does having a large motor neurone have
the larger the motor neurone the larger the connection to the muscle fibre so a more powerful contraction happens
what is the parasympathetic nervous system
lowers hr
calms us down
release acetylcholine
what is the sympathetic nervous system
prepares us for exercise
increases hr
fight or flight
release of adrenaline
the sympathetic and parasympathetic nervous systems are part of the?
peripheral nervous system which transmits information from the brain to parts of the body so they can adjust
what is a neuromuscular interaction
eg a muscle contraction involves the muscular system working with the nervous system
what is a motor unit
the motor neurone and the muscle fibres stimulated
what is the dependent on which the amount of fibres are stimulated
on the precision of the movement
describe the amount of fibres stimulated for powerful movements
many fibres are stimulated eg 2000 per unit when powerful movements occur, for example a basketball jumpshot
describe the amount of fibres stimulated for precise movements
few fibres are stimulated eg 1-5 per unit eg eye movement or spin bowling in the wrist
motor units are recruited depending on
the activity being undertaken
the need twitch/time response
what is a motor end plate
the point at which the motor neurone meets the muscle
describe the neuromuscular junction
calcium ions enter the synaptic knob which releases the transmitter chemical acetylcholine which aids the spread of the impulse across the synaptic cleft
if enough ACE is released there is a change in the permeability of the sarcolemma to sodium and potassium ions
now the muscle fibre has action potential giving it the capability to contract
what is the all or none law
Either all muscle fibres contract or none do, minimum threshold of stimulation must be reached
what is wave summation
Repeated nerve impulse with no time to relax so a smooth sustained contraction occurs, rather than twitches. one impulse is sent and then a second before the first one is received
