What is the direction of sodium ion flow through sodium channels in a photoreceptor cell in the dark?
A)from the cytoplasm into the extracellular space
B)from the smooth endoplasmic reticulum into the cytosol
C)from the extracellular space into the cytoplasm
D)from vesicles into the synapse

Question

Quizplus · Accepted Answer

In the dark, the photoreceptor cell is depolarized, causing sodium channels to open and allowing sodium ions to flow from the extracellular space into the cytoplasm. This influx of positive ions contributes to the depolarization of the cell, which eventually leads to the release of neurotransmitter at the synapse with the bipolar cell.

What Is the Direction of Sodium Ion Flow Through Sodium