Role of Sodium and Potassium Ions in Action Potentials

Very Hard Unit 2: Biological Bases Nervous System

The human nervous system exhibits a complex organization that enables it to respond to stimuli, control bodily functions, and process information. One critical aspect of this system is the membrane potential of neurons, which is crucial for the generation of action potentials. Neurons communicate through a variety of neurotransmitters, and their activity can significantly differ based on various influences.

When examining the properties of neurons, it is essential to understand how alterations in the ionic concentration inside and outside the neuron affect its ability to fire an action potential. For example, consider the transport of sodium and potassium ions across the neuronal membrane via specific ion channels. Which of the following accurately describes the role of these ions in initiating action potentials?

Sodium ions rushing into the neuron depolarize the membrane, while potassium ions exiting repolarize it.

Potassium ions entering neurons directly cause depolarization and the initiation of the action potential.

Sodium ions primarily remain inside the neuron, making it positively charged during resting potential.

Chloride ions play a significant role in depolarizing the cell membrane and are essential for action potentials.

Both sodium and potassium ions are equally involved in maintaining the resting potential of neurons.

Hint

Submitted16.1K

Correct11.4K

% Correct71%