Neuromuscular System And Muscle Fibre Types Flashcards
(19 cards)
What is the structure of neuromuscular system ?
Motor neurone
Motors units
Neuromuscular junction
Muscle fibres
CNS
Peripheral nervous system
What’s a motor neuron ?
Nerve cells that transmit brains instructions as electrical impulse to muscles
What’s a motor unit ?
A motor neurone and all the muscle fibres it innervates
What’s a neuromuscular junction ?
Where Motor neuron meet muscle fibre
What’s the CNS ?
Brain and spinal chord
What’s the peripheral nervous system ?
Nerves connecting CNS to rest of body muscles
What is a motor unit size ?
Refer to number of muscle fibres controlled by single motor neurone
Small motor unit size = little amount of muscle fibres, usually precise fine movement
Large motor unit size = lots of muscle fibres, usually for large powerful movements
How does a muscle contract ?
Action potential sent to muscle has to be great enough to reach action potential threshold if not met then no contraction
What’s acetylcholine ?
- Neurotransmitter
- Brings the electrical impulse into the muscle and triggers muscle fibres to contract
- It’s released at the end of a nerve and it binds to receptors in the muscle
What is the all or none law ?
Refer to how muscle will contract or not at all. Impulse has to reach action potential threshold in order to contract
What are the short term responses of neuromuscular system ?
- Increase nerve transmission
- Immediate muscle activation
- Motor unit recruitment
- Muscle fibre type recruitment
- Reflex response
- Blood flow regulation
What are the long term adaptations of neuromuscular system ?
- Increase motor unit recruitment.
- Enchanted muscle activation
- Muscle fibres types adapt
- Increase motor unit synchrony and improve motor neuron firing rate
- Summation of motor units
- Muscle hypertrophy
what are the three types of muscle fibres ?
Type 1 (aerobic, oxidative, slow twitch)
Type 2a (anaerobic, fast twitch, oxidative and glycolytic)
Type 2b (anaerobic, fast twitch, glycolytic)
What’s the structure of Type 1 muscle fibre ?
Fibre size = small
Number of capillaries = large
Number of mitochondria = large
Myoglobin store = high
PC store = low
Glycogen store = low
What’s the structures of type 2a muscle fibre ?
Fibre size = large
Number of capillaries = moderate
Number of mitochondria = moderate
Myoglobin store = moderate
PC store = high
Glycogen stores = high
What’s the structure type 2b muscle fibres ?
Fibre size = large
Number of capillaries = low
Number of mitochondria = low
Myoglobin store = low
PC store = high
Glycogen store = high
What are the characteristics of type 1 muscle fibres ?
Aerobic capacity = high
Fatigue resistance = high
Anaerobic capacity = low
speed of contraction = slow
Force of contraction = low
Activity = long distance
What are the characteristics of type 2a muscle fibre ?
Aerobic capacity = low/moderate
Fatigue resistance = low/moderate
Anaerobic capacity = high/moderate
Speed of contraction = fast
Force of contraction = high
Activity = 1500m
What are the characteristics of type 2b muscle fibres ?
Aerobic capacity = low
Fatigue resistance = low
Anaerobic capacity = high
Speed of contraction = fastest
Force of contraction = highest
Activity = sprint
