The difference in charge between the inside and outside of an axonal membrane is generated by what 3 forces?

1, High membrane permeability to potassium.

Which results from high number of potassium ion channels along the axon membrane compare to other ions. Therefore more potassium ions diffuse easily out of the axoplasm caring its positive ions along into the extracellular layer, making the inside (axoplasm) deficient in positive charge therefore more negative compare to the outside. Thus the inside of the axon is more negative than the outside layer.

2. Strong chemical gradient for potassium.

Basically, the inside of the cells is made up of more positively charged potassium ions, and some negatively charged anions.

However the strong chemical gradient allows continuous diffusion of potassium ions from the axoplasms into the outside layer. This occurs because of higher distribution of the positively charge potassium ions (high chemical gradients) of the inside compare to outside, therefore more positively charge ions potassium move out of the axopasm making the inside negative, (with already negatively charged anions present in the inside compare to extracellular layer)

3. High Electrochemical gradients.

Basically the inside of axons has more potassium ions, while the outside has more sodium ions in a neuron at rest.

The electrochemical gradients results from the combination of high negatively charges of anions inside the axoplasms, and the high concentration gradients of positively charged sodium ions outside the axon. The combination of these two forces called Electrochemical gradients pull sodium ions from the outiside with its positive charges into the negatively charged medium (inside) axoplasm. Creating reversal of charges; thus the inside is now more positive while the outside is negative.