Learn about depolarization, hyperpolarization, and action potentials in neurons with Khan Academy's comprehensive biology resources.

It works on the basic principle: action potential leads to opening up of Na+ ions and even more entering of Na into the cell, increased voltage opens up vesicles which release neurotransmitters.

Graded potentials are small changes in membrane potential that are either excitatory (depolarize the membrane) or inhibitory (hyperpolarize the membrane). Many excitatory graded potentials …

An action potential, unlike a graded potential, is an all-or-none event: it may or may not occur, but when it does occur, it will always be of the same size (is not proportional to the size of the …

Since action potentials are achieved by reaching a threshold, there is no way to reach a stronger action potential just from having a "stronger" depolarization. It isn't possible to have a stronger …

Can someone explain the difference between a grade potential and an action potential?

If you've learned about action potentials, you may remember that the action potential is an all-or-none response. That is, it either happens at its full strength, or it doesn't happen at all.

If the membrane potential becomes more positive than it is at the resting potential, the membrane is said to be depolarized. If the membrane potential becomes more negative than it is at the …

Action potentials travel down neuronal axons in an ion cascade. Positive ions (mostly sodium ions) flow into the cell body, which triggers transmembrane channels at the start of the axon to …

Graded potentials are small changes in membrane potential that are either excitatory (depolarize the membrane) or inhibitory (hyperpolarize the membrane). Many excitatory graded potentials …