This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
[{'content': 'In muscle cells, resting membrane potential is equal to the isoelectric potential of \nSelect and explain. \nA. Na+, B. Cl-, C. K+, D. Mg++', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The isoelectric potential of Cl- is -70mV and of K+ is -90mV.\nAccording to ‘Ganong’ and ‘Principles of Medical Physiology’, the actual measured RMP of a nerve fibre is -70mV rather than the calculated value of -90mV. \nSo in nerve fibres, the RMP is equal to or closer to the isoelectric potential of Cl-.\nWhereas in muscle cells, the RMP is -90mV, which is equal to the isoelectric potential of K+.', 'role': 'assistant'}]