Nerve Impulses

Question 1

Resting membrane potential

Answer 1

-70mV - before stimulation

Question 2

Stimulus applied to nerve cell

Answer 2

The membrane potential rises.

Question 3

Threshold membrane potential

Answer 3

-55mV - is reached after stimulation

Question 4

Threshold is reached

Answer 4

Sodium channels - open
Sodium ions go into the cell
The inside of the cell becomes positive and the outside become negative.

Question 5

Depolarization

Answer 5

Sodium goes into the cell
Membrane potential: -> 0 -> positive

Question 6

Action potential peak

Answer 6

Sodium channels - close
Potassium channels - open

Question 7

Repolarization

Answer 7

Potassium channels - open
Voltage inside the cell drops back to resting potential

Question 8

Hyperpolarization

Answer 8

Potassium channels - open
Membrane potential has dropped below its resting potential

Question 9

Sodium potassium pump

Answer 9

Potassium channels - close
returns membrane to resting potential
Moves 3 Na out and 2 K in
Outside of the cell is positive and inside is negative