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.
The nervous system is organized into two parts: the central nervous system, which consists of the brain and the spinal cord, and the peripheral nervous system, which connects the central nervous system to the rest of the body. An image depicting the central nervous system can be seen below. Nervous system, full body, anterior view.