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Biology of The Mind > The Action Potential > Flashcards

Flashcards in The Action Potential Deck (10):
0

What does a stimulus result in?

Small patch of of membrane becoming depolarised

1

Give the 4 phases of the action potential?

Resting, depolarisation, polarisation and afterhyperpolarisation

2

What direction are action potentials propagated in?

Axon hillock to the axon terminal

3

A larger stimulus will produce?

A greater number of action potentials

4

How does the permeability for NA and K change during and action potential?

At rest NA and K closed, during depolarisation NA open, during polarisation K open while NA close, undershoot K open and NA closed

5

What does the all-or-nothing hypothesis state?

Unless the depolarisation reaches the threshold of -50 mv an action potential will not fire

6

What is the absolute refractory period?

A period where no further action potential can fire as the cell has to recover to resting state. It ensures the unidirectionality of the action potential.

A huge stimulus could cause an action potential in this period.

7

What does the magnitude of the action potential do at different magnitudes of stimulus?

It varies, a large stimulus equals a greater magnitude

8

What happens do the amplitude of an action potential as it travels away from the site of production?

Decreases

9

What mechanisms are used to move ions across plasma membranes?

Ion pumps and ion channels