Answer:
A synapse is the gap between a neuron and its target cell. The target cell could be another neuron, a muscle cell, etc. It acts to communicate info from the presynaptic neuron to the postsynaptic cell. An action potential travels down the axon of the presynaptic neuron. Once it reaches the axon terminals, voltage-gated calcium channels open, causing an influx of Ca2+ ions into the neuron. This stimulates vesicles containing neurotransmitters within this presynaptic neuron to fuse with the plasma membrane. Thus, neurotransmitters are released into the synapse. Here, they travel to receptors on the postsynaptic cell. If this postsynaptic cell is a neuron, receptors for the neurotransmitter can be found on its dendrites. The neurotransmitter binds to its specific receptor on the dendrites of the postsynaptic neuron. One of the effects this binding may have is activation of second messengers within the postsynaptic neuron. These second messengers act to amplify the strength of the signal.
Step-by-step explanation: