00:01
An electrical signal known as an action potential, action potential, is sent down a motor neuron originating from the central nervous system.
00:13
The action potential quickly reaches the synaptic knob within one millisecond.
00:17
The arrival of the action potential opens calcium channels and the synaptic knob.
00:25
Synaptic vesicles release the neurotransmitter acetylcholine across the synaptic cleft.
00:36
Acetylcholine binds to its receptors on the motor in plate.
00:42
This results in the opening of voltage, voltage -gated sodium channel so that the sodium rushes into the muscle cell.
00:52
The influx of positively charged sodium ions into the muscle fiber depolarize it to threshold.
01:02
At threshold, voltage -gated sodium channels open and an action potential propagates down the t -tubules.
01:11
And towards the sarcoplasmic reticulum.
01:13
The sarcoplasmic reticulum releases a large amount of calcium that was stored within it...