Neuron Action Potential

Step 1

Stimulus — something (light, pressure, heat, a chemical) triggers a receptor on a neuron

Step 2

Transduction — the receptor turns that stimulus into an electrical signal

Step 3

If the signal is strong enough, an action potential fires — it's all-or-none, full strength or nothing

Step 4

Sodium (Na⁺) rushes in, then potassium (K⁺) flows out, and this wave travels down the axon

Step 5

At the end of the axon, neurotransmitters cross to the next neuron and bind its ligand-gated ion channels, opening them and possibly starting a new action potential

Step 6

The neuron resets to its resting state, using ATP, so it's ready to fire again