Resting Membrane Potential Flashcards
Excitatory cells start in non-excited state with a ______ voltage on the _____ of the cell
negative voltage on the interior
Cell ion concentrations K Na Ca Cl
K high intracellular
Na low intracellular
Ca extra low intracellular
Cl low intracellular
resting membrane potential is primarily due to permeability of the plasma membrane to
potassium ions
K leak channels are _____ x more prevalent than Na+ channels
100x more prevalent
measuring membrane potential measures the
difference between interior and exterior charge
electrostatic force is the combination of
diffusion force and electrostatic force
Diffusion force refers to
chemical gradient
electrostatic force referrs to
electrical gradient
nernst equation
61.5/charge of ion * log [x]out/[x]in
driving force is equal to
resting membrane potential minus [Eion] (from nernst)
why doesnt sodium influx into the cell
membrane is not very permeable to sodium
goldman equation
takes into account different ion concentrations and permeability
GHK equation
difference between nernst and GHK equation
GHK equation takes into account multiple ion concentrations as opposed to one ion
origins of membrane potential (3)
K diffusion potential (main contribution)
Na diffusion
Na+/K+ ATP pump
K diffusion potential is the _____ contributor to membrane potential
main contributor
changing ECF [K+] has large influence on RMP
Contribution of Na diffusion
minimal due to low permability
5mV positive
contribution of Na/K ATPase pump
minimal contribution
4mV more negative
Na/K ATPase pump retains a _____ Na concentration and a _____ K concentration
Low Na concentration
High K concentration
what is the major contributor to establishing resting membrane potential
Potassium leaking out of the cell
equilibrium potential is the membrane potential at which
the flow of ions across the membrane is zero
