Action Potential

Question 1

Does the intracellular fluid carry a + or - charge at rest?

Answer 1

Negative

Question 2

Does the extracellular fluid of a cell carry a + or - charge at rest?

Answer 2

Positive

Question 3

Membrane Potential

Answer 3

The electrical potential across a cell membrane.

Question 4

Resting Membrane Potential

Answer 4

The charge difference across the cell membrane when the cell is at rest (unstimulated)

Question 5

RMP Value

Answer 5

-70mV

Question 6

What are the 3 factors responsible for the presence of electrical voltage across the cell membrane?

Answer 6

1. Selective permeability of the cell membrane to different ions. (The cell is more permeable to K+ than Na+)
2. Difference in the concentration of ions inside and outside of the cells. (15X more Na+ than K+ outside & 30X more K+ than Na+ inside).
3. The presence of large, non-diffusable, - charged ions.