Neurons

• What are the three types of neurons?

  Sensory, relay, motor
• What is the function of neurons?

  Nerve cells that process and transmit messages through electrical and chemical signals
• The cell body includes a nucleus
• Branchlike structures called dendrites protrude from the cell body
• What do dendrites do?

  Carry nerve impulses from neighbouring neurons towards the cell body
• The axon is covered in a fatty layer of myelin sheath
• What does the myelin sheath do?

  Protects the axon and speeds up electrical transmission of the impulse
• What is the myelin sheath segmented by?

  Gaps known as nodes of Ranvier
• At the end of the axon are terminal buttons
• What do terminal buttons do?

  Communicate with the next neuron across the synapse
• Where are sensory neurons located?

  In the PNS in ganglia
• Where are relay neurons found?

  In the brain and the visual system
• Where are motor neurons found?

  CNS
• What does an action potential create?

  An electrical impulse that travels down the axon towards the end of the neuron
• When a neuron is activated by a stimulus, the inside of the cell becomes positively charged for a split second causing an action potential
• When a neuron is in a resting state, the inside of the cell is negatively charged compared to the outside