Functions Sensory – gather info from inside and outside the body Integrative – receive the info and decide what to do about it Motor – respond to the info

Cellular Structure Neurons – structural and functional unit Cell Body – cytoplasm and most organelles Dendrites – short, highly branched, bring in info Axons – long, sends impulse away from cell body Axon Terminal – releases neurotransmitters (chemical signals for the next cell)

Neuroglial cells (support cells) Schwann cells – around axons (PNS) Produce myelin - a lipoprotein that insulates axon to keep impulses in Nodes of Ranvier – narrow gaps in the myelin sheath

-Astrocytes – star shaped, structural support, scar tissue -Oligodendrocytes – form myelin in brain and spinal cord

-Microglial cells – CNS, support, phagocytize bacteria and cell debris -Ependymal cells – covers and lines CNS