MODEL
Explore an action potential
Scrub a voltage trace and inspect sodium and potassium channel states.
Model
Resting potential
-70 mV
Ion gradients and selective permeability support a negative resting potential. Voltage-gated channels are mostly closed.
The sodium–potassium pump maintains gradients over time; it does not directly cause the rapid downward stroke.
Schematic trace, not a recording. Axon channel timings vary. Stimulus strength above threshold usually affects firing frequency, not action-potential height.
Explain what you observed
Does a stronger stimulus produce a much taller action potential?
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Your study notes
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Connect this activity with your lesson notes and chapter practice.
Read a related learning guide →Practise Coordination & Control →Open the student notes folder ↗Concepts and sources
Curriculum connections: 5.2, 5.3. Selected concepts.
Read the supporting source ↗PMDC curriculum ↗Questions and explanations are original teaching material; these are not official exam questions.