I've used various versions of the Stick and I agree completely that it seems overpriced when you consider what it *is*, but the darn thing is good at what it *does*, and you'll quickly get over the cost.
In vertebrate species it consists of two main parts, the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS contains the brain and spinal cord. The PNS consists mainly of nerves, which are enclosed bundles of the long fibers or axons, that connect the CNS to every other part of the body.
Neurons are the basic unit of the nervous system. All cells of the nervous system are comprised of neurons. Neurons contain nerve processes which are finger-like projections that extend from the nerve cell body. The nerve processes consist of axons and dendrites which are able to conduct and transmit signals. Axons typically carry signals away from the cell body.