Neuron and Glial Cells

• Neurons


   Electrically excitable cells

   Results from separation of ion charge on either side of

  neuron membrane

   May exist in either resting/stimulated state

   Stimulated: neurons produce electrical impulses that are

  transmitted along axon

   Synapses – junctions where impulses are transmitted between

  neurons

   Enable transmission of impulses rapidly around body
• Dendrites - receive signals in the neurons
•  Different types of neurons

   Due to varying structure, function, and genetic make-up

   Three broad types:

   Sensory neurons

   transmit impulses from sensory receptors to other neurons

   Triggered by chemical and physical inputs (e.g., sound,

  touch, heat, light)

   Interneurons

   Neural intermediates found in brain and spinal cord

   Carry impulses from sensory  motor neurons (ex.

  reflexes) and other interneurons

   Motor neurons

   Important role in movement both voluntary and

  involuntary

   Transmit impulses from CNS  muscles/glands
• Glial Cells

  Gr. “glue”

  Functions:

  • Nourish neurons

  • Insulate axons

  • Regulate

  extracellular fluid

  surrounding

  neurons

  • Replenish some

  groups of neurons