What happens at the synapse

solution:
The neurons lie end to end in a chain to transmit the impulses in an animal body. The neurons are not connected. There occurs a very minute gap between terminal portion of axon of one neuron and dendron of the other neuron. This gap is called synapse. At the end of the axon, the electrical impulse sets off the release of some chemicals. These chemicals cross the gap (synapse), and start a similar electrical impulse in dendrite of the next neuron.

Synapses actually act like one way valves. This is because the chemical substance is present at only one side of the gap. In this way synapses ensures that nerve impulse travels only in one direction.