How is a nerve impulse transmitted across a cholinergic synapse?

Action potential reaches pre-synaptic knob.This stimulates voltage gated Ca2+ channels to open and Ca2+ to diffuse in.This causes vesicles containing ACh to bind to the pre-synaptic membrane and release ACh into the synaptic cleft.ACh diffuses across the cleft and binds to cholinergic receptors on the post-synaptic membrane.This causes Na+ channels to open and Na+ to diffuse into the post synaptic knob causing depolarisation.Depolarisation causes an action potential to be fired.