And remember, the resting membrane potential means that the inner portion is negatively charged and the outer portion, the extracellular portion of the cell membrane, is positively charged, as shown. So before any stimulus is applied, the membrane is negatively charged inside the cell and positively charged right outside the cell. Now, let's suppose our dendrites receive that signal and transmit that signal through the cytosol of the soma and to the exxon hillock. Now, if the stimulus is high enough, if it is equal to or exceeds the threshold value, then what that basically causes is the opening of the sodium voltage gated channels. And as soon as our stimulus is applied to a certain region, let's say this region, our channels, the sodium channels on the membrane open up and the sodium travels down its electrochemical gradient and from the outside and into that cell. So we have an influx of sodium into our cell.