The document describes the process of an action potential in a neuron. A neuron's resting potential is around -70 mV; when it is excited to threshold around -40 mV, sodium channels open causing rapid depolarization. Sodium channels then close and potassium channels open, repolarizing the membrane back to resting potential before entering an absolute refractory period with hyperpolarization below resting potential.

2. 1. 40 mV
2. -70 mV
3. Resting potential
4. Excitation to threshold
5. Na+ channels open
6. Depolarization
7. Na+ channels close
8. K+ channels open
9. Absolute refractory
10.Hyper polarization
11.K+ channels close, active transport resumes