Which structure helps keep the epithelial cell layer intact?

• A. Basement membrane
• B. Myoepithelial cells
• C. Adipose tissue
• D. Smooth muscle

Answer: (A)

The basement membrane anchors the epithelium to the underlying connective tissue, keeping the epithelial layer intact. It’s a thin, supporting sheet produced by both the epithelial cells (basal lamina) and surrounding connective tissue (reticular lamina) that provides mechanical stability, helps organize the tissue, and provides signals that maintain cell polarity and cohesion. This attachment layer resists shear forces and serves as a scaffold during repair, which is why it’s the structure most responsible for keeping the epithelial sheet intact. The other options have roles in secretion, gland function, or deeper tissue structure, but they don’t serve as the primary attachment and support for the epithelial layer.