Name the two layers that constitute the basement membrane.

• A. Basal lamina
• B. Reticular lamina
• C. Lamina propria
• D. Basement coat

Answer: (A)

The basement membrane is a two-layer structure that anchors epithelium to the underlying connective tissue. The layer closest to the epithelium is the basal lamina, secreted by epithelial cells, and it provides a dense, supportive sheet. Deeper is the reticular lamina, produced by connective tissue fibroblasts and linked to the basal lamina by anchoring fibers. Together these two layers form the basement membrane. The lamina propria is the connective tissue beneath the epithelium and not part of the basement membrane, and “basement coat” is not the standard term for its two-layer composition.