Lesson Plan

• Describe the structural components of a myelinated neurone that enable saltatory conduction.
• Explain how voltage‑gated Na⁺ channels at the nodes of Ranvier generate and propagate an action potential.
• Analyse the key factors (myelin thickness, internode length, axon diameter, temperature) that affect conduction velocity.
• Compare the speed and energy efficiency of saltatory conduction with continuous conduction in unmyelinated axons.

• Projector and slide deck showing diagrams of myelinated axons.
• Printed handout of the node‑of‑Ranvier diagram.
• Physical model of a neurone (axon, myelin sheath, nodes).
• Worksheet with short questions and a comparison table.
• Whiteboard and markers.

Begin with a quick video clip of a reflex action to highlight the need for rapid signalling. Ask students to recall how signals travel in unmyelinated fibres and what limitations they face. State that today they will uncover why myelinated neurones transmit impulses so much faster and how this relates to everyday function.

1. Do‑Now (5'): Students list differences between myelinated and unmyelinated axons from prior lessons.
2. Mini‑lecture with slides (10'): Review axon structure, myelin sheath, nodes of Ranvier.
3. Interactive model demo (8'): Use the physical model to illustrate “jumping” of the impulse between nodes.
4. Guided practice (12'): Worksheet activity where groups fill a table comparing factors affecting velocity.
5. Think‑Pair‑Share (5'): Students explain in their own words why myelin increases resistance and reduces capacitance.
6. Formative check (5'): Quick quiz via Kahoot on key concepts and the speed equation.

Summarise how the insulated internodes and clustered Na⁺ channels enable saltatory conduction, reinforcing the four factors that modulate speed. Exit ticket: each student writes one real‑world example where rapid neural transmission is critical; assign a short homework to create a labelled diagram of a myelinated axon.