Final answer:
Preganglionic fibers are myelinated and relatively short, while postganglionic fibers are unmyelinated and longer. The terms 'preganglionic neuron' and 'postganglionic neuron' are sometimes used to describe the projections, but usually the term 'neuron' includes the cell body in the ganglion.
Step-by-step explanation:
An axon from the central neuron that projects to a sympathetic ganglion is called a preganglionic fiber or neuron. These preganglionic fibers are myelinated and relatively short because the sympathetic ganglia are adjacent to the vertebral column.
On the other hand, postganglionic fibers are the axons from the ganglionic neurons that project to the target effector directly. These fibers are unmyelinated and longer compared to preganglionic fibers, as they have to travel a relatively greater distance from the ganglion to the target effector.
It's important to note that the terms 'preganglionic neuron' and 'postganglionic neuron' may be used to describe the projection from the central neuron to the ganglion, and from the ganglion to the target, respectively. However, typically the term 'neuron' refers to the entire cell and includes the cell body in the ganglion.