In the peripheral nervous system, which cellular junction permits diffusion of ions and small molecules directly between neighboring cells?

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Multiple Choice

In the peripheral nervous system, which cellular junction permits diffusion of ions and small molecules directly between neighboring cells?

Gap junctions create channels that directly connect the cytoplasm of neighboring cells, allowing ions and small molecules to diffuse from one cell to another. This direct cytoplasmic bridge enables rapid electrical coupling and metabolic sharing between cells, which is important for coordinated activity in the peripheral nervous system, such as communication between support glial cells like Schwann cells. Desmosomes and hemidesmosomes are adhesion structures that anchor cells to each other or to the extracellular matrix; they do not form diffusion pathways. Tight junctions seal the space between cells to prevent paracellular diffusion. Therefore, the junction that permits direct passage of ions and small molecules between neighboring cells is gap junctions.

Gap junctions create channels that directly connect the cytoplasm of neighboring cells, allowing ions and small molecules to diffuse from one cell to another. This direct cytoplasmic bridge enables rapid electrical coupling and metabolic sharing between cells, which is important for coordinated activity in the peripheral nervous system, such as communication between support glial cells like Schwann cells.

Desmosomes and hemidesmosomes are adhesion structures that anchor cells to each other or to the extracellular matrix; they do not form diffusion pathways. Tight junctions seal the space between cells to prevent paracellular diffusion. Therefore, the junction that permits direct passage of ions and small molecules between neighboring cells is gap junctions.

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