Graded vs. Action Potential: Key Differences Explained
Graded potential is a small, localized change in membrane voltage that can vary in size; action potential is an all-or-nothing electrical spike that travels the length of a neuron.
People mix them up because both involve ion flow and voltage shifts, yet one is like a whisper at a doorway while the other is a stadium wave—same stadium, totally different impact.
Key Differences
Graded potentials fade with distance and can be excitatory or inhibitory; action potentials always reach +30 mV, regenerate at each node, and never lose strength.
Which One Should You Choose?
If you’re studying synaptic chatter, focus on graded potentials. To understand nerve impulses or anesthesia targets, zoom in on action potentials.
Can graded potentials trigger action potentials?
Yes, if enough graded potentials summate to cross the threshold, an action potential fires.
Why don’t action potentials diminish like graded potentials?
Action potentials reset themselves via voltage-gated channels, ensuring the signal stays strong along the axon.