Question

When voltage-gated Na+ channels of a resting neuron open,

A) Na+ enters the neuron.
B) Na+ leaves the neuron.
C) the neuron depolarizes.
D) A and C
E) B and C

Answer 1

When voltage-gated Na+ channels of a resting neuron open, Na+ enters the neuron and depolarizes the membrane.

Step-by-step explanation:

A nerve impulse opens the Na+ channel, which makes Na+ enter the cell and depolarizes the membrane. As sodium ions rush into the cell, depolarization actually reverses the charge across the membrane from -70mV to +30mV. This change in the membrane potential causes voltage-gated K+ channels to open, and K+ begins to leave the cell, repolarizing it.