nodes of Ranvier

Examples of nodes of Ranvier in the following topics:

• Introducing the Neuron

  • The synapse is the chemical junction between the axon terminals of one neuron and the dendrites of the next.
  • Periodic gaps in the myelin sheath are called nodes of Ranvier.
  • At these nodes, the signal is "recharged" as it travels along the axon.
  • This neuron diagram also shows the oligodendrocyte, myelin sheath, and nodes of Ranvier.
  • The above image shows the basic structural components of an average neuron, including the dendrite, cell body, nucleus, Node of Ranvier, myelin sheath, Schwann cell, and axon terminal.

• Stages of the Action Potential

  • As these positive ions rush in, the membrane of the stimulated cell reverses its polarity so that the outside of the membrane is negative relative to the inside.
  • Once the electric gradient has reached the threshold of excitement, the "downswing" of repolarization begins.
  • In myelinated axons (axons covered by a myelin sheath), this process is described as saltatory because voltage-gated channels are only found at the nodes of Ranvier, and the electrical events seem to "jump" from one node to the next.
  • The amplitude of an action potential is independent of the amount of current that produced it.
  • The frequency of action potentials is correlated with the intensity of a stimulus.