Why do Na⁺ ions enter the cell when voltage-gated Na⁺ channels are opened in neurons?
A)because the Na⁺ concentration is much higher outside the cell than it is inside
B)because the Na⁺ ions are attracted to the negatively charged interior
C)because the Na⁺ ions are actively transported by the sodium-potassium pump into the cell
D)both A and B
E)both A and C

Question

Quizplus · Accepted Answer

When voltage-gated Na⁺ channels are opened in neurons, Na⁺ ions enter the cell because of the concentration gradient (higher concentration outside the cell than inside) and the attraction to the negatively charged interior of the cell. The sodium-potassium pump actively transports Na⁺ ions out of the cell, not into the cell. Therefore, the best choice is D, both A and B.

Why Do Na⁺ Ions Enter the Cell When Voltage-Gated Na⁺