Solve this: Q During the transmission of nerve Impulse through a nerve fibre, the potential on the inner - Biology - Environmental Issues

Question

Solve this:

Q During the transmission of nerve Impulse through a nerve fibre,
the potential on the inner side of the plasma membrane has which
type of electric charge :-

(1) first positive, then negative and continue to be negative

(2) first negative, then positive and continue to be positive

(3) first positive, then negative and again back to positive

(4) first negative, then positive and again back to negative

Shailaja Mestry · Accepted Answer

Dear Student,

Plasma membrane of a non-conducting neuron is positive on the
outside and negative inside The difference in charge is about 70 to
90 mV which is called as resting potential and the membrane is said
to be polarized A typical value of resting potential is
-70mV

When a plasma membrane of neuron is
stimulated, its permeability changes and sodium potassium pump stop
operating which results in the positive charge inside and negative
charge outside The nerve fibre
is said to be in action potential or depolarized The action
potential inside the membrane is about +30 mV

After a period of action potential,
sodium pump operates again and membrane will get resting potential
of -70mV by repolarization

Thus, Option (4) first
negative, then positive and again back to negative , is
correct

Regards,