Contribution of Na+/K+ pump to the development of RMP is:
Na+/K+-pump is electrogenic. It causes 3 positive charges (Na+) to be pumped out for 2 positive charges (K+) pumped into the cell. Thus, with the activity of the pump, the number of positive charges becomes less. Relatively, the number of negative charges become more. Thus, the pump on its own, contributes about - 4 mV to the membrane potential. The pump contributes a small potential directly. However, the remaining major potential can be said to be an indirect contribution of the pump. The pump causes concentration gradients of Na+ and K+ to be established across the membrane. These concentration gradients, in turn, cause the diffusion of these ions across the membrane. The diffusion of ions is responsible for development of major fraction of RMP.
- 90 mV
- 89 mV
- 86 mV
- 4 mV
Membrane potiential