events that occur at a chemical synapse

step 5

ion channels open and allow ions to flow across membrane

step 1

nerve impulse arrives at a synaptic end bulb of the presynaptic neurons

step 3

Exocytosis of synaptic vesicles and release neurotransmitters

step 4

The neurotransmitter molecules diffuse across synaptic cleft and bind to neurotransmitter receptors in the postsynaptic neuron's plasma membrane

step 2

calcium channels open and calcium ions flow into synaptic bulb end

step 6

depolarization will occur