nodes of Ranvier
(ran-veer)
The small gaps in the myelin sheath between successive glial cells along the axon of a neuron; also, the site of high concentration of voltage-gated ion channels.
nomograph ...
The medullary sheath undergoes interruptions in its continuity at regular intervals, giving to the fiber the appearance of constriction at these points: these are known as the nodes of Ranvier (Figs. 631 and 633).
Action potentials are only regenerated at the unmyelinated nodes of Ranvier which are spaced intermittently between myelinated segments.
Between these cells there are small gaps in the myelin sheath called the Nodes of Ranvier. Action potentials are able to jump from one node to the next one down the neuron incredibly rapidly.
Schwann cells prevent diffusion of ions
Flow of current between adjacent nodes of Ranvier
Thus, depolarisation only at nodes of Ranvier
Action potential jumps from node to node ...
The exposed areas are called nodes of Ranvier: they contain very high densities of sodium channels and action potentials jump from one node to the next, without involving the intermediate axon, a process known as saltatory conduction.
which is formed by either of two types of glial cells: Schwann cells ensheathing peripheral neurons and oligodendrocytes insulating those of the central nervous system. Along myelinated nerve fibers, gaps in the sheath known as nodes of Ranvier occur ...
These produce the myelin sheath that surrounds many axons in the central nervous system (brain and spinal cord).
Astrocytes. These — often star-shaped — cells are clustered around synapses and the nodes of Ranvier where they perform ...
 See also: Neuron, Action, Cells, Nodes, Myelin
  
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