AP PSYCHOLOGY

Detailed explanation-1: -During an action potential, sodium ions diffuse into the axon. The axon is depolarized when potassium ions diffuses out of it. Depolarization occurs when potassium ions diffuses into the axon.

Detailed explanation-2: -To summarize, sodium ions (Na+) enter the nerve membrane during depolarization and potassium ions (K+) leave the nerve membrane during repolarization.

Detailed explanation-3: -The inside of the neuron is more negatively charged than the outside. Figure 4.1. For a typical neuron at rest, sodium, chloride, and calcium are concentrated outside the cell, whereas potassium and other anions are concentrated inside. This ion distribution leads to a negative resting membrane potential.

Detailed explanation-4: -K+ is more concentrated inside than outside the cell. Organic anions are more concentrated inside than outside the cell. Cl-is more concentrated outside than inside the cell. Na+ is more concentrated outside than inside the cell.

Detailed explanation-5: -The sodium and chloride ion concentrations are lower inside the cell than outside, and the potassium concentration is greater inside the cell. These concentration differences for sodium and potassium are due to the action of a membrane active transport system which pumps sodium out of the cell and potassium into it.