Resting Membrane Potential

Front 1

resting potential.

Back 1

membrane potential of neuron between action potential

Front 2

typical resting potential

Back 2

-85 mV

Front 3

what is the charge inside the cell at rest?

Back 3

negative

Front 4

whys is resting potential important ? (3)

Back 4

1. The resting potential affects whether solutes enter or leave the cell.
2. The normal resting potential is partially responsible for creating a driving force for the
entry of Na+ into the cells, which is coupled to the transport of many other molecules
into or out of the cell.
3. In cells, such as neurons, skeletal muscle and cardiac muscle cells, the presence of a
membrane potential enables the production and transmission of action potentials.

Front 5

what is requisite for for a potential difference across a membrane?

Back 5

permeable to at least one ion (cation or anion)

Front 6

what determines an ion's equilibrium potential?

Back 6

concentration gradient and electrical forces

Front 7

equilibrium potential equation

Back 7

E=

Front 8

are membrane potential and equilibrium potential the same thing?

Back 8

no

Front 9

if equilibrium potential and membrane potential are equal, what is the net current?

Back 9

Zero

Front 10

what is the relationship in a steady state at rest between Na+ and K+? (3)

Back 10

1. There is a K+ current and K+ flows out of the cell.
2. There is a Na+ current and Na+ flows into the cell.
3. The outward K+ current equals the inward Na+ current, therefore the membrane potential
does not change.

Front 11

what would happen naturally to K+ and Na+ levels without the pump mechanism?

Back 11

the intracellular K+ concentration would fall and the intracellular Na+ concentration would increase

Front 12

in what direction does the Na+/K+ pump each respective ion?

Back 12

K+ in --- Na+ out

Front 13

how is current carried through a membrane?

Back 13

ions moving through channels that are specific for the particular ion.

Front 14

what determines The specific ion conductance?

Back 14

the number of specific channels of that type that are open.

Front 15

When Em = Eion, what is the effective voltage difference across that membrane?

Back 15

there is no effective voltage difference for that ion across the membrane and there is no flow of that ion

Front 16

which ion is most responsible for changing the resting membrane potential? why?

Back 16

K+, it has a much higher transference than Na+