Work through the following questions individually or in small groups.
Remember that the resting membrane potential is going to be a function of the permeability properties of the membrane to sodium and potassium, and the magnitude and direction of sodium and potassium fluxes across the membrane will depend on the electrochemical gradients for each ion. Altering permeability will alter ion flux magnitude; altering ion concentration on either side of membrane will also change the gradients that govern ion fluxes.
Use the following diagram as a model:
1. What is the effect of increasing the extracellular concentration of KCl on the resting membrane potential?
2. What is the effect of decreasing the extracellular concentration of KCl on the resting membrane potential?
3. What is the effect of increasing the extracellular concentration of NaCl on the resting membrane potential?
4. What is the effect of decreasing the extracellular concentration of NaCl on the resting membrane potential?
5. What is the effect of increasing K+ permeability on the resting membrane potential?
6. What is the effect of decreasing K+ permeability on the resting membrane potential?
7. What is the effect of increasing Na+ permeability on the resting membrane potential?
8. What is the effect of decreasing Na+ permeability on the resting membrane potential?
