Describe the events that occur at synaptic junction that result in an action potential in the post synaptic membrane.

An action potential arrives at the pre synaptic membrane which initiates the opening of Ca2+ channels. The influx of Ca2+ ions will cause vesicles containing neurotransmitters to fuse with the pre-synaptic membrane. The neurotransmitters will leave the pre-synaptic membrane via exocytosis and diffuse across the synaptic clef. The neurotransmitters will bind to complementary receptors on the post-synaptic membrane. Binding of neurotransmitter to the receptor cause the ligand-gated Na+ channels on the post-synaptic membrane to open , allowing Na+ to move into the post-synaptic membrane. The entry of enough Na+ ions will depolarise the post synaptic membrane and an action potential will be generated.