Neural Control and Coordination Question 25

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

[2004]

(a) $K^{+}$into the cell

(b) $K^{+}$and $Na^{+}$out of the cell

(c) $Na^{+}$into the cell

(d) $Na^{+}$out of the cell

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Answer : c

Hints & Solutions

(c) In a resting state of the neural membrane, $Na^{+}$concentration is higher on the outer side and $K^{+}$concentration is more within the cell. This concentration gradient is maintained by voltage gated channels. Hence if diffusion is allowed $Na^{+}$would enter the cell and $K^{+}$would leave.