Action potential

Question 1

Why does action potential start

Answer 1

The dendrites receive a signal through ligand-gated ion channels which can only open when the neurotransmitter is bound to them.

Question 2

What has a higher concentration of positive ions, inside or outside of cell

Answer 2

The outside of the cell

Question 3

What is the resting electrical charge of a cell

Answer 3

-70mV

Question 4

What charge does depolarisation change the cell to

Answer 4

-55mV

Question 5

WHat is depolarisation

Answer 5

Making the inside charge of the cell more positive

Question 6

WHat is step 1 action potential

Answer 6

cell membrane changes to -55mV and opens ion channels on the axon

Question 7

What is step 2 action potential

Answer 7

Sodium channel opens, sodium rushes in, as sodium is positively charged, cell membrane charge changes to +40mV. (depolarisation)

Question 8

What is step 3 action potential

Answer 8

More sodium channels open as depolarisation travels along the axon, the signal travels from cell body to terminal

Question 9

What is step 4 action potential

Answer 9

Sodium channels shut and potassium channels open after this and they pump ions out. Potassium is more negative than sodium so makes cell membrane charge more negative (repolarisation).

Question 10

What is step 5 action potential

Answer 10

The potassium pump drops the membrane potential down to -80mV- refractory period-nothing happens. Stops neuron firing again too soon.

Question 11

WHat is step 6 action potential

Answer 11

A mix of sodium-potassium pumps swap over ions to restore membrane potential back to -70mV.