Explain Depolarization is conduction of nerve impulse.

Explanation

1. When a nerve fibre is stimulated, sodium voltage gate opens and make the axolemma permeable to `Na^(+)` ions, meanwhile the potassium voltage gate closes.
2. As a result, the reate of flow of `Na^(+)` ions into the axoplasm exceeds the rate of flow of `K^(+)` ions to the outside fluid [ECF}.
3. Therefore, the axolemma becomes positively charged inside and neagtively charged outside. THis reversal of electrical charge is called Depolarization.
4. During depolarization, when enough `Na^(+)` ions enter the cell, the action potential reaches a cetain level, called Threshold potential [-55MV].
5. Due to the rapid influx of `Na^(+)` ions, teh membrane potential shoots rapidly up to + 45mV which is called teh spike potential. This is followed by Repolarization.