What is a synapse? Describe how it works.

A synapse is the junction where nerve cells (called neurones) meet. An electrical signal can pass from one neurone to another across the synapse. When the signal reaches the end of the neurone, it causes a chemical to be released from vesicles into the synapse. These chemicals are called neurotransitters. The neurotransmitter diffuses across the synaptic cleft and bind to receptors on the membrane of the next neurone. This then creates an electrical impulse in the second neurone, so the signal has been passed across the synapse. Signals can only travel in one direction across a synapse because the neurotransmitter receptors are only on the second neurone. Some neurotransmitters inhibit the electrical impulse being made in the second neurone, rather than stimulating it.