From wikipedia article RESTING potential: "there is no actual measurable charge excess in either side. That occurs because the effect of charge on electrochemical potential is hugely greater than the effect of concentration so an undetectable change in concentration creates a great change on electric potential."
the effect of charge on electrochemical potential significantly larger then the effect of charge on concentration - is this a general statement or true in all cases?
And if charge is more significant then concentration in influencing electrochemical potential why does a small change in concentration greatly effect electropotential? Or does it mean electrochemical potential? Either way how does it make any sense, is it correct or nonsense and what is the exact meaning behind the message?
other questions I have:
1) What is the reason Na+ stays at its location right across the barrier on the extracellular side of the membrane? Diffusion? Electrochemical potential? Electric Charge.. if so because of Attraction or Repulsion?
2) If the answer is the electrochemical gradient/potential, because it is trying to move to a "less" positive potential.. if its located extracellularlly isn't that the "great unknown" where any molecules/cells/protein etc. are able to float by and possibly influence it? What happens if one of these has a "LESS" positive potential then the membrane that Na+ is currently attracted?
3) Why can't Na+ be used for the entire process to establish the same voltage interactions leading from resting to action potential (as long as thier was less concentration intracellularly... if it is about LESS positivity ..Or vice versa for K+?)?
I am preparing for ACSM certification exam, so any help is appreciated.