Hyponatremia has no effect on the RMP (resting membrane potential) because: (A) The cell membrane is impermeable to Na+, (B) ECF Na+ concentration is high, (C) Intracellular K+ concentration is high, (D) Equilibrium potential for Na+ is +60 mV
Answer is D. Resting membrane potential depends on the concentration of potassium ion and not on sodium ion. (REF TEXTBOOK OF MEDICAL PHYSIOLOGY GEETHA N 2 EDITION, 23)