Which surface of epithelial cells faces away from the lumen and toward the underlying tissue?

Which surface of epithelial cells faces away from the lumen and toward the underlying tissue?

• A. Apical surface
• B. Basal membrane
• C. Lumen-facing surface
• D. Basolateral surface

Answer: (D)

Epithelial cells have distinct surfaces oriented in relation to the hollow space (lumen) and the tissues underneath. The surface that faces the lumen is the apical surface. The opposite boundary that interacts with the underlying connective tissue is the basal surface, which contacts the basement membrane. The term basolateral describes the sides of the cell that are away from the lumen—toward the underlying tissue and toward neighboring cells. So, when a surface faces away from the lumen and toward the underlying tissue, it is the basolateral surface. The basement membrane itself is a structure the basal surface sits on, not the surface of the cell. The lumen-facing surface is the apical surface.

Epithelial cells have distinct surfaces oriented in relation to the hollow space (lumen) and the tissues underneath. The surface that faces the lumen is the apical surface. The opposite boundary that interacts with the underlying connective tissue is the basal surface, which contacts the basement membrane. The term basolateral describes the sides of the cell that are away from the lumen—toward the underlying tissue and toward neighboring cells.

So, when a surface faces away from the lumen and toward the underlying tissue, it is the basolateral surface. The basement membrane itself is a structure the basal surface sits on, not the surface of the cell. The lumen-facing surface is the apical surface.