Question

During the transmission of nerve impulse through a nerve fibre, the potential on the inner side of the plasma membrane has ____ type of electric change.

• A. First positive, then negative and continue to be negative
• B. First negative, then positive and continue to be positive
• C. First positive, then negative and again back to positive
• D. First negative, then positive and again back to negative

Answer 1

The correct option is D

First negative, then positive and again back to negative

Before the generation of an action potential, the neuron is in resting state that is -70mV, inside the cell. During action potential or transmission of nerve impulse, the membrane potential inside the neuron rises upto 30mV. After the action potential has passed the neuron returns back to its resting state i.e. at -70mV.