It has no spines and no synapses are formed on its membrane. The axon is the cell extension that has the job of generating and carrying electrical currents called nerve impulses. These impulses are triggered at the soma end of the axon and travel down the axon to its many endings. With the thousands of dendritic branches and telodendria all tangled together, neural tissue often resembles a thicket of cell fibers in which the neuron somas are embedded like raisins in a fruitcake. The dimensions of neurons are astounding.
Many axons seem enormously long to be growing out of somas the size of pinpoints.
For example, the motor neurons that contract the muscles of your foot have their invisibly small cell bodies in the spinal cord about a third of the way up your back, which means that their axons, which reach all the way down your leg, are well over three feet in length. The tiny speck of a soma, which controls the chemistry of the entire cell, must manufacture all the molecules needed by that whole length of axon and then send them floating slowly down to their distant destinations. Not all neurons have lengthy axons, though. So far we have been discussing type I , neurons which must have long axons because they provide the connections between areas within the CNS or between cord and muscle. One of the things that enables one part of the brain to perform one function while another does something quite different is that each part has its own unique pattern of connections between type II neurons.