Neurons do not make direct contact but are separated by synapses. Impulses cross a synapse by means of a neurotransmitter. Describe the process of neurotransmitter release at a synapse. You may use a labelled diagram.

Action potential arrives at axon terminal of presynaptic neuron

Voltage-gated Ca2+ channel opens

Ca2+ enters the cell

Ca2+ signals to vesicles

Vesicles move to the membrane

Neurotransmitters are released by exocytosis

Neurotransmitters diffuse across the synaptic cleft and bind to receptors on the postsynaptic membrane