MEDICAL PHYSIOLOGY

Detailed explanation-1: -As we discussed in the practical class, the Nernst equation is able to give a value for the voltage that must exist across the membrane in order to balance a chemical gradient that exists for the ion in question.

Detailed explanation-2: -The Nernst equation calculates the equilibrium potential (also referred to as the Nernst potential) for an ion based on the charge on the ion (i.e., its valence) and its concentration gradient across the membrane.

Detailed explanation-3: -RMP: Theory: Nernst Equation. The value of the equilibrium potential for any ion depends upon the concentration gradient for that ion across the membrane. If the concentrations on the two sides were equal, the force of the concentration gradient would be zero, and the equilibrium potential would also be zero.

Detailed explanation-4: -The equilibrium potential is calculated using the Nernst equation [3] [1]: Em = RT/zF * log([ion outside the cell]/[ion inside of the cell]). Z will be 1 for a monovalent ion such as K+, and 2 for a divalent ion such as Ca2+ and so on.

Detailed explanation-5: -At equilibrium, the reaction quotient Q=Keq. Also, at equilibrium, G=0 and G=−nFE, so E=0. The Equation above indicates that the equilibrium constant Keq is proportional to the standard potential of the reaction.