Resting potential + Action potential

Question 1

what is the resting state of an axon called?

Answer 1

resting potential

Question 2

in the resting state, What is the potential difference across the axon?

Answer 2

-70mV

Question 3

What is the 1st stage of resting potential?

Answer 3

sodium-potassium pumps in axon membrane transport:

• 3 sodium ions out of axon
• FOR EVERY 2 potassium ions moving into axon (using active transport)

Question 4

Why is the inside of the axon more negative than the outside?

Answer 4

More positive ions are being pumped out than in

3 sodium in :2 potassium out

Question 5

what is the stage after resting potential?

Answer 5

depolarisation

Question 6

what happens when stimulus is applied?

Answer 6

an action potential occurs

Question 7

what is depolarisation?

Answer 7

Na voltage gated channels open - Na floods into axon

positive Na ions causes resting potential to increase (+35mv)

Question 8

what happens once membrane potential reaches +35mv?

Answer 8

Na channels close

Question 9

what is repolarisation?

Answer 9

K voltage gated channels open
K floods out of axon
(membrane is polarised)

Question 10

What is hyper-polarisation?

Answer 10

too many potassium ions flood out

potential difference is under -70mv