Neurones

• A neuron has a long fiber known as an axon
• Axon

  • Insulated by a fatty sheath
  • Contains small, uninsulated sections known as nodes of Ranvier
• These spaces are known as nodes of Ranvier
• Sheath

  Made of myelin
• Myelin

  A substance made by specialized cells known as Schwann cells
• Myelin formation

  Schwann cells wrap around the axon along its length
• The electrical impulse does not travel down the whole axon, but jumps along its length from one node to the next
• Saltatory conduction

  The process of the electrical impulse jumping from one node to the next along the axon
• Less time is wasted transferring the impulse from one cell to another
• Cell bodies of neurons

  • Contain many extensions called dendrites
  • Can connect to many other neurons
  • Receive impulses from them forming a network for easy communication