The site where chemical communication occurs between neurons is what?

• A. Axon
• B. Dendrite
• C. Synapse
• D. Myelin

Answer: (C)

The site of chemical communication between neurons is the synapse. When an action potential reaches the end of a neuron, calcium ions enter and trigger release of neurotransmitters into the tiny gap called the synaptic cleft. These chemicals cross the gap and bind to receptors on the next neuron, converting the chemical signal into an electrical change that can either excite or inhibit the postsynaptic cell. This is different from the axon, which carries signals away from the body; dendrites, which primarily receive signals; and myelin, which speeds conduction by insulating the axon but does not mediate chemical signaling. So the synapse is where the chemical message is transmitted between neurons.