The central nervous system (CNS) is the processing center for the nervous system. It receives information from and sends information to the peripheral nervous system. The two main organs of the CNS are the brain and spinal cord.he brain processes and interprets sensory information sent from the spinal cord. Both the brain and spinal cord are protected by three layers of connective tissue called the meninges. Within the central nervous system is a system of hollow cavities called ventricles.
The edge of something is the end of it, the outer limit. You can sit on the edge of your desk, on the edge of a chair, on the edge of a cliff. As stated by someone else, sitting on the edge of your seat is used to indicate tension or anticipation. You are ready to jump up out of the seat as quickly as possible.
Definition of edge. a sharp side formed by the intersection of two surfaces of an object; he rounded the edges of the box. a strip near the boundary of an object; he jotted a note on the margin of the page. a slight competitive advantage; he had an edge on the competition. the attribute of urgency; his voice had an edge to it.