Biology / Unit 12 Bio 2827 short lesson, about 20 seconds
Chemical Synapse: Neurotransmitter Release
Captions available
The idea
At a chemical synapse, an arriving action potential opens calcium channels, triggering synaptic vesicles to release neurotransmitter that diffuses across the cleft and binds postsynaptic receptors.
In practice
Acetylcholine released at a neuromuscular junction opens postsynaptic sodium channels, depolarizing the muscle cell.
Where people slip
Chemical synapses carry a brief delay, roughly one millisecond, since neurotransmitter must diffuse across the cleft before the signal continues.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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