_IMG_48_06aMembranePotentialA-L.jpg
<strong>Neuron ionic gradients.</strong>

The concentrations of <b>Na<sup>+</sup></b> and <b>Cl<sup>-</sup></b> are higher in the extracellular fluid than in the
cytosol of a neuron.

The reverse is true for <b>K<sup>+</sup></b>.

These gradients are maintained by the sodium-potassium _FIG_../ch07/sodium-potassium_pump.html	pump
and cause the ions to diffuse back across the membrane and create a resting _SIZ_resting_potential.html	potential.