Question

The axon shows enhanced permeability to ${Na}^{+}$ after stimulation, leading to ___

• A. $K^{+}$ activation
• B. ${Na}^{+}$ exit
• C. Polarisation
• D. Depolarisation

Answer 1

The correct option is D

Depolarisation

Depolarization is a positive change from the resting potential achieved by increased permeability to an ion. This is in response to a signal initiated at dendrite, where ${Na}^{+}$ channels open within the membrane of the axon. As ${Na}^{+}$ are more concentrated outside of the neuron, the opening of sodium channels causes a passive influx of sodium resulting in depolarisation.