Periodically along the surface of the wrapped glial cell there are gaps approximately every 1-2mm. Each gap allows the environment external to the myelin sheath to be exposed to the axon for approximately 1-2υm. These gaps in the sheath are called the '''Nodes of Ranvier''' and are important in the conduction of impulses along the axon. | Periodically along the surface of the wrapped glial cell there are gaps approximately every 1-2mm. Each gap allows the environment external to the myelin sheath to be exposed to the axon for approximately 1-2υm. These gaps in the sheath are called the '''Nodes of Ranvier''' and are important in the conduction of impulses along the axon. |