biology / Human Systems / free
Action Potential
Push a membrane past threshold and follow the signal through time.
Follow the mechanism1 / 3
Inputs change membrane voltage. Ion gradients and selective permeability establish a resting state that can be nudged by incoming signals.
membrane potentialbelow threshold
Focus the idea
stimulus54%
threshold62%
staterest
phase0%
The stimulus is below threshold, so the membrane returns toward rest without firing a full spike.
This simplified trace shows threshold, spike shape, and recovery timing. It does not reproduce every molecular detail of a real neuron.
Guided journey
1 / 4Follow the mechanism.
01 / Begin at rest
The membrane has a resting voltage created by ion gradients and selective permeability.
What changes next: The neuron is ready to respond, but no spike is occurring yet.
04 / PRACTICE
0 / 3 checkedMake the biology yours.
Answer from the model, then use the explanation to connect the visual mechanism to the biological rule.
CHECK 1 / 3