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': 'What is/are effect on membrane when extracellular concentration of K+ is decreaseda) ↓magnitude of RMPb) ↑negativity of the membranec) ↑magnitude of RMPd) ↓negativity of membrane \nSelect and explain. \nA. bc, B. c, C. ac, D. ad', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Points to note\nConcentration of ions\n\nNa+ concentration higher in ECF\nK+ concentration higher in ICF\nCl- concentration higher in ECF\nK+ leak channels allow K+ to move from ICF to ECF\nNa+ is prevented from entering to the cell.\nInside the cell, negativity is higher because Na+K+ pump pushes out 3 Na+ while taking in 2 K+.\nK+ leaks to ECF, along the concentration gradient, until the electrical gradient prevents further leak (inside the cell is more negative compared to ECF). So electrical gradient wants to pull positive charges towards ICF while concentration gradient wants to pull K+ towards ECF. This brings a balance in movement of K+.\n\nNow, if the concentration of K+ in ECF is increased\n\nThe concentration gradient of K+ is decreased.\nLess leaking of K+ from ICF to ECF.\nMore positivity of the membrane OR Less negativity of the membrane OR Decreased magnitude of RMP.\n\nIf the concentration of K+ in ECF is decreased\n\nThe concentration gradient of K+ is increased.\nMore leaking of K+ from ICF to ECF.\nMore negativity of the membrane OR Less positivity of the membrane OR Increased magnitude of RMP.', 'role': 'assistant'}]