A rather tame ltxnsp was recently found on Easter Island by a retired neurophysiologist. He reported the following measurements of ECF and ICF concentrations (in millimoles): ICF ECF Pr+ 0 150 Na+ ? ? K+ 10 100 Cl- 109 250 HCO3- 1 10 so this is the question: He lacked the proper instruments for determining Na+ concentrations, but was rather certain that no other major ions were present in the ECF and ICF. Can you calculate either concentration for him? I think we use the Nernst eqn in this case to figure it out which is Em= 58/ z * log (xo/xi). correct me if i'm wrong. So Na and Cl is transported via the symporter so only charges are opposite. therefore we find the Em of Cl-? Then after that we find what's K? But then I don't get how to use those to tie it to find Na. I'm confusing myself here. Can someone help me out.