Definition: A portion of a line which starts at a point and goes off in a particular direction to infinity. Try this Adjust the ray below by dragging an orange dot and see how the ray AB behaves. Point A is the ray's endpoint.
Plant cell cross-section, showing the membrane. Animal cell cross-section, showing the membrane. Resting membrane potential is the difference in voltage of the fluids inside a cell and outside a cell, which is usually between -70 to -80 millivolts (mV). View slideshow of images above.
â¢ The resting membrane potential of a cell is the electrochemical state of a cell (neuron) at rest, i.e the membrane permeability at rest. â¢ It is the transmembrane potential of the resting cell-at which there is no net movement of a particular ion across the cell membrane. â¢ It is the potential that would be maintained if there were no action potentials, synaptic potentials,or other active changes in the membrane potential.