Highest equilibrium potential is that for:-
- Ca+2 equilibrium potential is +129 millivolts- Equilibrium potential is calculated by Nernst equation NERNST EQUATION: (Electromotive force in millivolts)- It is concentration of paicular Ion on either side of the membrane. For calcium- Ca+2 concentration gradient from outside to inside (C1 /C2) is almost 10,000.- Intracellular Ca+2 is very low, So Ca+2 moves in very fast.- Ca+2 is divalent cation, So it will carry double the number of positive charges to inside.- Therefore, when Ca+2 reaches equilibrium, charge on the membrane will be very high. ( +129mv- highest of all the Ions in the body). For chloride- EP in nerve= -70mv- EP in muscle = -89mv RMP of muscle(-90mv) is closest to equilibrium potential of Cl-.- If membrane potential is very close to EP of any Ion then that Ion movement will not be that great- If membrane potential is far away from EP of any ion, then the ion movement will be much greater
Na+
K+
CI-
Ca++
Membrane potiential