How does a synapse transmit an impulse?

The action potential arrives the membrane the depolarises Ca2+ channels open and they enter the neurone the presence of Ca2+ causes the synaptic vesicles containing neurotransmitters to fuse with the presynaptic membrane the neurotransmitter are released by exocytosis into the synaptic cleft the neurotransmitters bind with the receptors on the postsynaptic membrane opening the cation channels (Na+) the postsynaptic membrane can now depolarise and initiate an action potential once released from the receptors they are broken down by enzymes found in the synaptic cleft and diffuse away or be taken in by the presynaptic neurone