The Action Potential

THE ACTION POTENTIAL

Full Image (binary/octet-stream)

STAGE ONE

Stage One (binary/octet-stream)

At resting state, the inside of the cell is negatively charged and the outside surrounding the cell is positively charged. 

STAGE TWO

Stage Two (binary/octet-stream)

When the neurone is sufficiently activated by a stimulus, the cell gradually becomes positively charged in a process known as depolarisation. 

STAGE THREE

Stage Three (binary/octet-stream)

As an impulse passes through the neurone, it gradually switches the charges. 

STAGE FOUR

Stage Four (binary/octet-stream)

The action potential travels down the axon towards the terminal buttons in a process known as firing. Since the impulse is moving, the charges of the previous sections switch back to their original state. 

STAGE FIVE

Stage Five (binary/octet-stream)

The action potential is an 'All-or-Nothing' event, meaning the impulse must travel all the way through the neurone, or not at all. If depolarisation doesn't reach a certain threshold, then there can be no action potential.