Resting Potential

Question 1

What is a graded potential?

Answer 1

Graded potential receives the stimulus.
- temporary, localized change in electrical potential of neurone
- caused by external stimulus
- amplitude varies with strength of stimulus

Question 2

Where does graded potential occur on a neurone?

Answer 2

In the cell body before the axon.

Question 3

How does Na+ pass through a graded potential membrane?
(Production of a Graded Potential 2)

Answer 3

• chemical neurotransmitter binds to receptor sites on chemically regulated Na+ channels
• channels open
• Na+ enters cell down electrochemical gradient
• membrane is depolarised

Question 4

What happens when Na+ ions are inside the cell membrane?
(Production of a Graded Potential 3)

Answer 4

Produces local Na+ current that depolarises adjacent membranes

Question 5

What does the size of a potential depend on?

Answer 5

Degree of stimulus mechanical/chemical
- length depends on stimulus duration

Question 6

Can graded potentials travel (propagate along the cell)?

Answer 6

No

Question 7

What other potential do graded potentials set up?

Answer 7

Action potential - second type of potential