MEDICAL PHYSIOLOGY

Detailed explanation-1: -The diffusion of potassium ions out of a neuron causes regain of resting potential. The resting membrane potential is restored due to action of voltage gated (K+) channels which open due to membrane depolarisation and cause efflux of (K+) ions out of the neuron. It continues till the resting potential becomes-70 mV.

Detailed explanation-2: -After depolarization, the cell membrane becomes relatively permeable to positively charged potassium ions, which diffuse outward from the inside of the cell, where they normally occur in rather high concentration. The cell then resumes the negatively charged condition characteristic of the resting potential.

Detailed explanation-3: -After a cell has been depolarized, it undergoes one final change in internal charge. Following depolarization, the voltage-gated sodium ion channels that had been open while the cell was undergoing depolarization close again. The increased positive charge within the cell now causes the potassium channels to open.

Detailed explanation-4: -Depolarization also opens voltage-gated K+ channels, allowing K+ efflux, which, together with rapid Na+ channel inactivation, quickly repolarizes the membrane during the falling phase of the action potential. This enables the cell to propagate electrical signals quickly and with high efficiency.

Detailed explanation-5: -Potassium Can Cross Membrane at Rest Electrochemical gradients drive potassium out of the cell, removing positive charge, making the cell’s membrane potential more negative, in the direction of potassium’s equilibrium potential.