This is a representation of the serotonin system.

Serotonin is released into the space between the "sending" nerve cell and the "receiving" nerve cell. When serotonin is received on the surface of the "receiving" cell, it stimulates or activates serotonin receptors. Stimulation of these receptors generates an impulse and allows message to move forward.

An important way serotonin is removed from this system
is by a serotonin uptake pump.