Question: Which of the following correctly states the direction followed by the specified ions when their voltage-gated channels open? A graph of transmembrane potential with membrane potential measured in millivolt as a function of time measured in milliseconds. Letter A indicates the start of the curve at the level of negative 70 millivolts. At 0.5 milliseconds the curve rises sharply to plus 30 millivolts. This rise is marked with letter B. Letter C indicates a sharp decrease from plus 30 millivolts at 1 millisecond to a point below negative 70 millivolts at 2 milliseconds. Letter D indicates a smooth rise back to negative 70 millivolts from 2 milliseconds to 4 milliseconds. Letter E indicates the point where the curve is back to negative 70 millivolts at 5 milliseconds. Na+ ions move out of the axon; K+ ions move in. Na+ ions move into the axon; K+ ions move out. Both Na+ and K+ ions move out. Both Na+ and K+ ions move in. Need Assignment Help?