question_answer

Nerve impulse initiates with the movements of

A)  \[{{K}^{+}}\]

B)  \[N{{a}^{+}}\]

C)  \[C{{a}^{+}}\]

D)  \[M{{g}^{+}}\]

Correct Answer: B

Solution :

In normal resting stage, nerve fibres are in form of polarized stage with a resting membrane potential of -70 mv. When a nerve impulse travels through nerve fibre, depolarization takes place due to influx (ie, inside movement) of \[N{{a}^{+}}\] ion. \[C{{a}^{+}}\] ion helps in blood clotting bone formation and muscle contraction. \[M{{g}^{++}}\] ion helps in muscle contraction and bone formation. \[{{K}^{+}}\] ion also helps in muscle contraction.