Myelin G-Ratio & Saltatory Conduction Velocity

This simulator renders a segment of myelinated axon — alternating myelin internodes and bare nodes of Ranvier — and computes real conduction velocity from the classic Hursh diameter rule and Rushton's g-ratio optimum, the same relationships used to explain why vertebrate motor axons cluster around a g-ratio of roughly 0.6–0.7. Drag the diameter and g-ratio sliders to watch the fiber's geometry and its computed velocity change together, or dial in demyelination severity to see how losing myelin at a fraction of internodes forces those segments into slow, continuous conduction — the same mechanism that slows or blocks signal propagation in demyelinating diseases such as multiple sclerosis. Fire an action potential to watch it hop from node to node at the resulting speed.