U6T4 – Nerves: Action Potentials

Stimulation ( either by a generator potential in a receptor cell or a neurotransmitter binding to a receptor on a postsynaptic membrane) caused which type of channel to open?

After a stimulation has occurred, why do ions move out of an axon?

What do we call the process happening at '3' on the above diagram?

What ion is moving during process '3' on the above diagram?

Which direction are the ions moving during process 3 on the above diagram?

Name the process happening at '4' on the above diagram?

Which ions are moving across the membrane during process '4'?

What causes a change in the type of channels that are open at stage '4' ?

Name stage 5 on the above diagram ( spell it carefully!)

What has happened at stage 5?

Which of the events (A - F above) starts depolarisation? Type the letter in the box

Which of the events ( A- F above) requires ATP ? ( Type the letter in the box)

Put the above events ( A-F) in order for the passage an action potential.

The period of time after an action potential, when another action potential cannot pass along that section of a neurone is called the ____________ period ( Watch your spelling).

Why can't a second action potential pass immediately after the first ?

In order for an action potential to be triggered, a certain number of sodium channels must open, each setting a change in the potential difference.

What name is given to this change in potential difference that must be reached ? (Type your answer)

True or false: If more sodium channels are opened by a stimulus, then the action potential which is generated is bigger.

True or False: If too few sodium channels are opened by a stimulus on an neurone membrane, then no action potential is generated.

True or False: A stronger stimulus will generate more frequent action potentials.