EVERYDAY SCIENCE

Detailed explanation-1: -In myelinated axons, Schwann cells form the myelin sheath. The sheath is not continuous. Individual myelinating Schwann cells cover about 1 mm of an axon-equating to about 1000 Schwann cells along a 1-m length of the axon. The gaps between adjacent Schwann cells are called nodes of Ranvier.

Detailed explanation-2: -Two nodes of Ranvier (indicated by arrows) are separated by a distance of approximately 350 Mm; the diameter of the fiber is greater than 12 Mm. The nodes are shown at higher magnification in the insets.

Detailed explanation-3: -The Nodes of Ranvier are the gaps between the myelin insulation of Schwann cells which insulate the axon of neuron. The Node of Ranvier is the 1-2 micrometre gap between the glial cells of the myelin sheath. These glial cells are called Schwann cells, and they help to electrically insulate the neuron.

Detailed explanation-4: -Since there’s no influx of ions from outside of the membrane until the next node, the capacitance and resistance of the membrane is exponentially decaying the voltage. So, if the distance between the nodes was too long, the voltage would just die off and the AP wouldn’t propagate.