This chemical transmission of nerve
impulses causes the axon and the dendrites to develop specialized structures that
facilitate it. Thus, dendrites have thousands of “spines” sticking
up out of their surface. The bulb-like terminal buttons of the axons, which
secrete the neurotransmitters, are positioned opposite these spines. But
the form of these component structures of the synapse
varies tremendously, as does the overall
form of the neurons themselves. |