-CNS includes the brain and the spinal cord while the PNS includes everything else
-2 main types of cells: neurons and glial cells
-glial cells support the neurons, nourish, remove waste, defend against infection
-glial cells also provide supporting framework for nervous system tissue
-neurons are the basic structural and functional unit of the system
-neurons conduct electrochemical signals and are organized into tissues called nerves
-all neurons share 4 common features: dendrites, a cell body, an axon, branching ends
-dendrites: -short, branching terminals
- receive nerve impulses from other neurons or sensory receptors
- relay the impulse to the cell body
-cell body: - contains nucleus
- site of cell's metabolic reactions
- processes input from dendrites
-axon: - conducts impulses away from cell body and to terminal ends
-branching ends: -release chemical signals into the space between it and the receptors or dendrites of neighbouring cells