A Level PE - The Neuromuscular System

Definition

Keyword

Muscle fibres with a slow contraction speed and better adapted to lower intensity exercise EG long distance running

Muscle fibres that fatigue quickly and used for highly explosive events EG 100m

A motor neurone and its muscle fibres

A sustained muscle contraction caused by a series of fast repeating stimuli

When the strength of a contraction changes by altering the number and size of the muscle's motor units

Nerve cells which transmit the brain's instructions as electrical impulses to the muscles

Where the motor neurone and the muscle fibre meet

Muscle fibres more resistant to fatigue and used where longer bursts of energy are needed EG 1500m

Definition

Keyword

Where a sequence of impulses has to be of sufficient intensity to stimulate all of the muscle fibres in a motor unit in order for them to contract. If not, none of them contract

These detect how far and how fast a muscle is being stretched and produce the stretch reflex

Stretch -> Contraction -> Relax -> Stretch

Where there is a repeated nerve impulse with no time to relax so a smooth, sustained contraction occurs, rather than twitches

These are activated when there is tension in a muscle

When there is tension in a muscle but no visible movement

Where there is a sudden relaxation of the muscle in response to high tension