The structure and function of the nervous system as it puts us into contact with our environment is described. Section 1 presents a detailed discussion of the structure of the brain, drawing an analogy to a computer, and discusses the sensory input function. The transport system is then explained in a description of the transmission of sensory impulses along the cerebro-spinal neural pathways. The third section, arrival at the brain, discusses reception or processing function in the brain itself. Implications for the diagnosis of neurologically handicapped learners in terms of pinpointing the area of dysfunction are made. A bibliography is included. (CL)