1.3 The neuromuscular system Flashcards
What is the role of the sympathetic nervous system
Prepares the body for exercise (Fight or Flight)
Increases HR
What is the role of the parasympathetic nervous system
To relax the body - slow down HR
What are the 2 main types of muscle fibre
Slow twitch (Type 1) Fast twitch (Type 2)
What type of exercise are slow twitch fibres best suited for
Low intensity
How do slow twitch fibres produce their energy
Aerobically
What type of exercise are fast twitch fibres best suited for
Short intense bursts
How do fast twitch fibres produce most of their energy
Anaerobically
What are the two types of fast twitch muscle fibres
Type 2a fast oxidative glycolytic
Type 2x fast glycolytic
What is the contraction speed of type 1 fibres
Slow (110 metres per second)
What is the contraction speed of type 2a muscle fibres
Fast (50 metres per second)
What is the contraction speed of type 2x muscle fibres
Fast (50 metres per second)
What is the motor neurone size of type 1 fibres
Small
What is the motor neurone size of type 2a fibres
Large
What is the motor neurone size of type 2x fibres
Large
What is the motor neurone conduction capacity of type 1 fibres
Slow
What is the motor neurone conduction capacity of type 2a fibres
Fast
What is the motor neurone conduction capacity of type 2x fibres
Fast
What level of force is produced by type 1 fibres
Low
What level of force is produced by type 2a fibres
High
What level of force is produced by type 2x fibres
High
What is the level of fatiguability of type 1 muscle fibres
Low
What is the level of fatigability of type 2a fibres
Medium
What is the level of fatigability of type 2x fibres
High
What is the mitochondrial density of type 1 fibres
High
What is the mitochondrial density of type 2a fibres
Medium
What is the mitochondrial density of type 2x fibres
Low
What is the level of myoglobin content in type 1 fibres
High
What is the level of myoglobin content in type 2a fibres
Medium
What is the level of myoglobin content in type 2x fibres
Low
What is the level of capillary density in type 1 fibres
High
What is the level of capillary density in type 2a fibres
Medium
What is the level of capillary density in type 2x fibres
Low
What is the aerobic capacity of type 1 fibres
Very high
What is the aerobic capacity of type 2a fibres
Medium
What is the aerobic capacity of type 2x fibres
Low
What is the anaerobic capacity of type 1 fibres
Low
What is the anaerobic capacity of type 2a fibres
High
What is the anaerobic capacity of type 2x fibres
Very high
Enzyme activity level in type 1 fibres
Low
Enzyme activity level in type 2a fibres
High
Enzyme activity level in type 2x fibres
Very high
How can you change muscle fibre type
Training to increase fibre size
What is a motor unit
A motor unit and its muscle fibres
What is a motor neurone
Nerve cells which transmit the brains instructions as electrical impulses to the muscle
What is a neuromuscular junction
Where the motor neurone and the muscle fibre meet
What is the all or none law
A sequence of impulses had to be of sufficient intensity to simulate all of the muscle fibres in a unit for it to contract, if not none of them will contract
What are the two ways to increase the strength of a contraction
Wave summation and spatial summation
What does PNF stand for
Proprioceptive neuromuscular facilitation
What is PNF
An advanced stretching technique largely considered to be one of the most effective techniques for increasing flexibility
What are muscle spindles
A type of proprioceptor that detect how far and fast a muscle is being stretched
What reflex do muscle spindles produce
Stretch reflex
What are the golgi tendon organs
A type of proprioceptor that are activated when there is tension in a muscle
What is autogenic inhibition
Where there is a sudden relaxation of the muscle in response to high tension.
What receptors cause autogenic inhibition
Golgi tendon organs
Describe how to perform PNF stretching
- A passive stretch is performed with the help of a partner to the point where tension is felt, if stretched too far the stretch reflex will occur
- Then isometrically contracts the muscle for at least 10 seconds by pushing their leg against a partner who supplies enough resistance to keep the leg stationary. This helps to delay the stretch reflex
- As the leg is lifted again the golgi tendon organs cause the agonist muscle to relax, increasing range of movement