Resting vs Action Potential: Key Differences Explained
Resting potential is the steady electrical charge across a neuron’s membrane when it’s inactive. Action potential is the brief, rapid reversal of that charge that fires the neuron.
Students often lump both under “nerve signals” and confuse quiet readiness with the actual electrical spike. It’s like mixing the silent tension of a drawn bow with the arrow’s flight—both matter, but they serve opposite roles in one process.
Key Differences
Resting potential sits around –70 mV, maintained by K+ leaks and the Na+/K+ pump. Action potential spikes to +30 mV when voltage-gated Na+ channels open, then resets. The first is stable; the second is a fleeting wave.
Which One Should You Choose?
Choose resting potential when studying baseline neural readiness or drug effects on membrane stability. Choose action potential when exploring nerve transmission, muscle contraction, or disorders like epilepsy where firing patterns go haywire.
Examples and Daily Life
A sleeping brain shows mostly resting potentials; a sudden hand jerk from a hot pan is an action potential cascade. EKG and EEG charts translate these shifts into the squiggly lines doctors read.
Can action potentials occur without resting potential?
No. The resting potential sets the required voltage difference; without it, there’s no threshold to cross.
Which ion matters most for each?
K+ dominates resting potential, while Na+ rushes drive the rising phase of action potential.