Question

The factors that are responsible for the maintenance of the resting membrane potential of a neuron is/are

• A. High resting state permeability for $K^{+}$ ions
• B. Membrane impermeable to proteins
• C. Lack of ${Na}^{+}$ leakage channels
• D. Membrane impermeable to ${Na}^{+}$ ions.

Answer 1

Answer: (A), (B), (C)

Lack of ${Na}^{+}$ leakage channels

The resting membrane potential of a neuron is established and maintained by the following factors:

1. Presence of large number of $K^{+}$ leakage channels on cell membrane, allowing the high amount of $K^{+}$ inside the cell to freely diffuse out.

2. There are very few ${Na}^{+}$ passive channels, therefore the high ${Na}^{+}$ outside cannot freely enter the cell.

3. Activity of Na-K pump, that carries outside 3 positive ions, for every 2 positive ions brought inside.

4.The neuronal membrane is impermeable to negative ions, as there are no negative ion leakage channels.

5. Large negatively charged proteins are present inside the cell and cannot move out of the cell as the cell membrane is impermeable to proteins.