Animation of a portion of a cell showing the resting potential.

• The animation starts where the concentrations of all ions are equal inside and outside of the cell. At this point V_m=0 (light green color).
• When you click (Play), the Na⁺/K⁺ pump begins pumping Na⁺ out and K⁺in. This establishes a concentration gradient shown by the blue and red triangles: Na⁺ 'want to go in' and K⁺ 'want to go out'. You can skip to this point by clicking (Gradients established).
• Once the gradients are established, you can add a K⁺ channel which will let K⁺ ions out of the cell, making V_m negative (orange color). This is the resting potential
• Once the gradients are established, you can add a Na⁺ channel which will let Na⁺ ions into the cell, making V_m positive (pink color). This is involved in the action potential

Key to Symbols used in animation

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Evelyne Tschibelu 2003