Resting Membrane Potential

Question 1

Excitatory cells start in non-excited state with a ______ voltage on the _____ of the cell

Answer 1

negative voltage on the interior

Question 2

Cell ion concentrations 
K
Na 
Ca 
Cl

Answer 2

K high intracellular
Na low intracellular
Ca extra low intracellular
Cl low intracellular

Question 3

resting membrane potential is primarily due to permeability of the plasma membrane to

Answer 3

potassium ions

Question 4

K leak channels are _____ x more prevalent than Na+ channels

Answer 4

100x more prevalent

Question 5

measuring membrane potential measures the

Answer 5

difference between interior and exterior charge

Question 6

electrostatic force is the combination of

Answer 6

diffusion force and electrostatic force

Question 7

Diffusion force refers to

Answer 7

chemical gradient

Question 8

electrostatic force referrs to

Answer 8

electrical gradient

Question 9

nernst equation

Answer 9

61.5/charge of ion * log [x]out/[x]in

Question 10

driving force is equal to

Answer 10

resting membrane potential minus [Eion] (from nernst)

Question 11

why doesnt sodium influx into the cell

Answer 11

membrane is not very permeable to sodium

Question 12

goldman equation

Answer 12

takes into account different ion concentrations and permeability
GHK equation

Question 13

difference between nernst and GHK equation

Answer 13

GHK equation takes into account multiple ion concentrations as opposed to one ion

Question 14

origins of membrane potential (3)

Answer 14

K diffusion potential (main contribution)
Na diffusion
Na+/K+ ATP pump

Question 15

K diffusion potential is the _____ contributor to membrane potential

Answer 15

main contributor

changing ECF [K+] has large influence on RMP

Question 16

Contribution of Na diffusion

Answer 16

minimal due to low permability

5mV positive

Question 17

contribution of Na/K ATPase pump

Answer 17

minimal contribution

4mV more negative

Question 18

Na/K ATPase pump retains a _____ Na concentration and a _____ K concentration

Answer 18

Low Na concentration

High K concentration

Question 19

what is the major contributor to establishing resting membrane potential

Answer 19

Potassium leaking out of the cell

Question 20

equilibrium potential is the membrane potential at which

Answer 20

the flow of ions across the membrane is zero