What is the primary role of the basement membrane in epithelial tissues?

• A. It produces mucus
• B. It anchors the epithelium to connective tissue and acts as a selective barrier
• C. It forms the air-blood barrier
• D. It stores minerals

Answer: (B)

The basement membrane’s main job is to anchor the epithelium to the underlying connective tissue and act as a selective barrier between them. It sits between the epithelial cells and the connective tissue, providing structural support through connections with hemidesmosomes and integrins, so the epithelial layer stays attached and properly oriented. It also regulates which molecules diffuse from the connective tissue into the epithelium and vice versa, helping maintain tissue organization and guiding cell behavior during development and repair. While it can contribute to filtration in some organs, its primary function is the secure attachment and selective barrier role. It doesn’t produce mucus, isn’t the main component of the air-blood barrier, and doesn’t store minerals.