PE 2-Motor Units Flashcards
Motor Unit
A motor neurone plus all the muscle fibres it initiates.
Neurone
A type of nerve cell
Axon
Carries the action potential from the cell body to the neuromuscular junction.
Neuromuscular Junction
Where the moto neurone communicates with the muscle fibres across the synapse.
Synapse
The space between the neuromuscular junction and the skeletal muscle.
Motor end plate
Area of muscle fibre which establishes synaptic contract with the motor neurone.
Resting potential
Where there is a lower charge inside the neurone than outside the neurone.
Neurotransmitter
Chemical transmitters which diffuse across a synapse binding to receptors to initiate muscular contraction.
Action Potential
The electrical impulse carried down the axon.
Acetyl Choline
The neurotransmitter released at the neuromuscular junction and diffuses across the synapse.
All or Nothing Law
If the AP threshold is reached, all the muscle fibres in the motor unit are initiated. If the AP threshold is not reached then none of the muscle fibres are initiated.
