why dont depolarisation and action potential mean the same thing?

Question

why dont depolarisation and action potential mean the same thing? i cant quite figure out why

Answer 1

Action Potential means a spike/wave of electrical charges.

Depolarization is a stage of action potential wherein there is a rapid influx of Sodium(Na) through the voltage gated sodium channels

Answer 2

Simply because Action Potential is a general term which means the spike or wave of electrical charges. Depolarization is one stage in Action Potential wherein the polarized state is lost and the voltage goes positive and there is a rapid influx of Sodium due to the opening of the Voltage Gated Sodium Channels.

Answer 3

an action potential in a neuron consists of 3 distinct phases: 1. depolarization, 2. repolarization and 3. after-hyperpolarization.
Depolarization is the first phase of the action potential during which the cell membrane potential changes from -70mV (rest) to +30mV. This depolarization is caused by a sudden and dramatic increase in cell permeability for sodium.
The second phase of the action potential, repolarization, is when the membrane potential returns from +30mV back to resting levels at -70mV. The repolarization is caused by increased permeability to potassium.
Finally, the third, and last stage of the action potential: after-hyper-polarization. This occurs b/c potassium permeability remains elevated for a short period of time and the membrane potential is overshot; it actually goes to -94mV.
so, these 3 events are why an action potential and depolarization don't mean the same thing. Depolarization is part of an action potential, but the action potential does not solely consist of depolarization.

Answer 4

A depolarization of an excitable cell can fire an action potential. However, there is a threshold of depolarization that must be reached before an action potential can be fired. When it is, voltage-gated sodium channels open, and the positive ions sweep into the cell, causing more depolarization (a positive feedback system). But there can be depolarizations of the cell that are not sufficient to open the v-gated Na channels.