Question

In the resting state of the neural membrane, diffusion due to concentration gradients, if allowed would drive

• A. $K^{+}$ into the cell
• B. $K^{+}$ and $N{a}^{+}$ out of the cell
• C. $N{a}^{+}$ into the cell
• D. $N{a}^{+}$ out of the cell

Answer 1

The correct option is C $N{a}^{+}$ into the cell

In the resting nerve fibre, the cytoplasm inside the axon has a high concentration of $K^{+}$ and a low concentration of $N{a}^{+}$ in contrast to the fluid outside the axon. Thus, if diffusion occurs through concentration gradient, then $N{a}^{+}$ enters the fibre.