_Y_+60
_IMG_48_13ActionPotGenerat5.jpg
<strong>Undershoot.</strong><br>
Some <b>K<sup>+</sup></b> ions continue to diffuse through open channels, resulting in <strong>undershoot</strong>
before the membrane returns to its <span class="RED">resting potential</span>.<br> 
The Na<sup>+</sup> channels remain closed, preventing another <strong>depolarization</strong> in a brief
<span class="PURPLE">refractory period</span>.