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
High-Yield Explanation
Points to note
Concentration of ions
Na+ concentration higher in ECF
K+ concentration higher in ICF
Cl- concentration higher in ECF
K+ leak channels allow K+ to move from ICF to ECF
Na+ is prevented from entering to the cell.
Inside the cell, negativity is higher because Na+K+ pump pushes out 3 Na+ while taking in 2 K+.
K+ 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+.
Now, if the concentration of K+ in ECF is increased
The concentration gradient of K+ is decreased.
Less leaking of K+ from ICF to ECF.
More positivity of the membrane OR Less negativity of the membrane OR Decreased magnitude of RMP.
If the concentration of K+ in ECF is decreased
The concentration gradient of K+ is increased.
More leaking of K+ from ICF to ECF.
More negativity of the membrane OR Less positivity of the membrane OR Increased magnitude of RMP.