EVERYDAY SCIENCE

Detailed explanation-1: -Depolarization is caused when positively charged sodium ions rush into a neuron with the opening of voltage-gated sodium channels.

Detailed explanation-2: -During the depolarization phase, the gated sodium ion channels on the neuron’s membrane suddenly open and allow sodium ions (Na+) present outside the membrane to rush into the cell. As the sodium ions quickly enter the cell, the internal charge of the nerve changes from-70 mV to-55 mV.

Detailed explanation-3: -There is a higher concentration of potassium ions on the inside of the cell than on the outside.

Detailed explanation-4: -In neurons, potassium ions are maintained at high concentrations within the cell while sodium ions are maintained at high concentrations outside of the cell. The cell possesses potassium and sodium leakage channels that allow the two cations to diffuse down their concentration gradient.