membrane potential

Introduction

The electrical potential of the cytoplasm inside a cell membrane relative to the potential of the interstitial fluid or plasma outside the membrane. Under resting conditions, membrane potential of excitable tissues is negative, but becomes positive during an action potential.

Electrical potentials are produced by ATPases (Na+/K+ ATPase) that establish electrochemical gradients in conjunction with selective permeabilty of ion channels under different conditions.

Cardiac myocytes spend 30% of energy to maintain transmembrane potential.

Additional terms

• action potential
• cytoplasm
• plasma