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Biophysics & Medical Physics FAQ

The action potential velocity in a myelinated nerve fibre is increased by:

Saltatory conduction (action potential jumps between nodes of Ranvier). Myelin insulates the axon; the action potential jumps between nodes of Ranvier (saltatory conduction), greatly increasing speed vs. unmyelinated fibres.

Short Answer

Saltatory conduction (action potential jumps between nodes of Ranvier) is the best answer.

Biophysics questions work best when you translate anatomy or instrumentation back into plain physics: pressure gradients, flow, diffusion, energy deposition, imaging contrast, and signal-to-noise.

Myelin insulates the axon; the action potential jumps between nodes of Ranvier (saltatory conduction), greatly increasing speed vs. unmyelinated fibres.

Why This Answer Is Correct

This is a Medium-level question in Biophysics & Medical Physics. The prompt is really testing whether you can connect the concept to its defining physical relationship instead of picking a nearby-but-wrong term.

Clinical wording can hide a simple physics core. Strip the scenario down to transport, force, energy, or measurement first.

Choices At A Glance

  • A. Smaller axon diameter
  • B. More sodium channels
  • C. Saltatory conduction (action potential jumps between nodes of Ranvier)
  • D. Reduced membrane capacitance only

When similar options appear on an exam, eliminate the ones that break the core law, use the wrong units, or confuse a definition with a consequence.

Topic Snapshot

Topic: Biophysics & Medical Physics

Difficulty: Medium

Best next move: Re-state the governing law in your own words, then solve one more example from the same topic before moving on.