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Which ion has the greatest influence on the resting membrane potential of most neurons?

A. Sodium (Na⁺)
B. Potassium (K⁺)
C. Calcium (Ca²⁺)
D. Chloride (Cl⁻)

User Nicasio
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1 Answer

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Final answer:

Potassium (K+) is the ion with the greatest influence on the resting membrane potential of neurons due to its higher membrane permeability and the role of the sodium-potassium pump in maintaining the potential.

Step-by-step explanation:

The ion with the greatest influence on the resting membrane potential of most neurons is Potassium (K+). Neurons maintain a negative charge inside during their resting state, around -70 millivolts relative to the outside. This resting membrane potential is mainly due to a higher permeability of the neuron's membrane to K+ compared to other ions, such as Na+. K+ moves out of the cell via potassium leakage channels more readily than Na+ moves in. This movement of K+ ions out of the cell contributes to the negative charge inside. Additionally, the sodium-potassium pump exchanges three Na+ ions out of the cell for every two K+ ions it brings in, which also helps maintain the resting membrane potential.

User Bigskull
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