explain about the sodium potassium pump !
At resting stage of a neuron:
Axonal membrane is more permeable to K+ and nearly impermeable to Na+.It is impermeable to negatively charged proteins present inside the axoplasm. Thus, it does not let them go out.
As a result, the axoplasm has more concentration of K+ and negatively charged proteins, and less concentration of Na+. This creates a concentration gradient.
Gradient is maintained by the Sodium-Potassium Pump which pumps 3 Na+ out and 2 K+ in.