MEDICAL PHYSIOLOGY

Detailed explanation-1: -Neurons have a negative concentration gradient most of the time, meaning there are more positively charged ions outside than inside the cell. This regular state of a negative concentration gradient is called resting membrane potential.

Detailed explanation-2: -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-3: -When an action potential begins, the channels that allow sodium ions, Na+, to cross open up. Now during the resting potential phase, the outside of the axon is positively charged relative to the inside of the axon (Figure 7).

Detailed explanation-4: -Neurons actually have a pretty strong negative charge inside them, in contrast to a positive charge outside. This is due to other molecules called anions. They are negatively charged, but are way too big to leave through any channel. They stay put and give the cell a negative charge inside.