ANATOMY

Detailed explanation-1: -Generally, the channels of the neurons are closed and the membrane is said to be in a resting state. In this state, the charge of the inside of the cell membrane is more negative than the outside (approximately-70 millivolt).

Detailed explanation-2: -The cell interior contains higher concentrations of K+ and negatively charged proteins and DNA molecules while the cell exterior is more enriched in Ca2+ and Na+. K+ ions leak out of the cell down this concentration gradient through potassium channels leading to a net negative charge in the interior of the cell.

Detailed explanation-3: -A neuron at rest is negatively charged: the inside of a cell is approximately 70 millivolts more negative than the outside (−70 mV, note that this number varies by neuron type and by species).

Detailed explanation-4: -If channels that allow K+ to pass are opened, K+ will move down its concentration gradient (from inside to outside the cell). As a result, there will be a loss of positive charge from the inside of the cell, so the inside will become negatively charged with respect to the outside.

Detailed explanation-5: -Because of this, a slight excess of positive charge builds up on the outside of the cell membrane, and a slight excess of negative charge builds up on the inside. That is, the inside of the cell becomes negative relative to the outside, setting up a difference in electrical potential across the membrane.