The Nernst Equation – Intuition, Formula & Full Derivation

Where does the Nernst potential come from — and how do we calculate it? In this video we build up the Nernst equation from scratch: starting with the physical intuition (why ions move and why they stop), then the simplified formula you'll actually use in physiology, and finally a full first-principles derivation showing exactly where the formula and the 61.5 mV factor comes from. ⏱ Chapters 0:00 Ion gradients and the resting membrane potential 1:46 The Nernst equation 3:11 Worked example: potassium 3:52 Full derivation 5:56 What's next