During the transmission of nerve impulse through a nerve fibre, the potential on the inner side of the…
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 change?
first positive, then negative and continue to be negative
first negative, then positive and continue to be positive
first positive, then negative and again back to positive
first negative, then positive and again back to negative.
Solution
The first channels to open are the sodium ion channels, which allow sodium ions to enter the cell. The resulting increase in positive charge inside the cell (up to about +40 $\mathrm{mV}$ ) starts the action potential. This is called the depolarization of the membrane. Potassium ion channels
Related Theory
Events that characterize the transmission of a nerve impulse. (Ref. to Fig. 25.7)
