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
input reaches−58 mV
threshold−55 mV
statesubthreshold
trace time0%
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 with typical values (rest −70 mV, threshold near −55 mV, peak near +35 mV). It does not reproduce every molecular detail of a real neuron.
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