Heidi A. Everett
The central nervous system is composed of the brain and spinal cord. The brain acts as the main processor for all activities of the body. The spinal cord acts as a transport system carrying the electrical impulses away from or towards the brain to maintain a balance or homeostasis between the various organ systems of the body (Hopson, 2006).
Neurons and glia are the two types of cells that make up the tissues of the central nervous system. Glial or neuroglia do not participate in processing information but they are critically important in providing structural and metabolic support for the neurons in the brain and also getting rid of dead cells within the brain (Grabowski, 2000). It is interesting to note that there are many more glial cells than there are neurons in the brain and they make up the majority of the brain's weight (Beatty, 1995). Students may benefit from knowing that the definition of glia is "glue." This can provide the students with a way in which to distinguish between the neuron and a glia cell (Grabowski, 2000).
