ABSTRACT
This chapter discusses the function and organization of nervous systems. Nervous systems can be simply described as aggregations or collections of neurons which are arranged to work in a coordinated function. The nervous system is made up of two different cell types: neurons and glial cells. Neurons are the workhorses of the nervous system. The function of glial cells is one of supporting the work of neurons. Perhaps one of the best known types of glial cells are the Schwann cells that wrap themselves around the axon of neurons to form the myelin sheath. The resting membrane potential can be easily understood if we consider the distribution of ions across the neuronal cell membrane together with the differential permeability of the neuronal cell membrane to various ions. Action potentials are transient changes in membrane polarity, when the interior of the neuron changes from being negatively charged to being positively charged for a few milliseconds.
