Question

activation gates in the cell membrane for voltage - gated sodium ion channels open into the
multiple choice
endoplasmic reticulum
cytoplasm
nucleus
extracellular fluid

Explanation:

Voltage - gated sodium ion channels in the cell membrane open to allow sodium ions to flow into the cell. Sodium ions are more concentrated in the extracellular fluid, and the activation gates open into the extracellular fluid to allow the influx of sodium ions when the appropriate electrical signal is present.

Answer:

D. Extracellular fluid