Laminin is a major component of which basement membrane layer?

• A. Reticular lamina
• B. Basal lamina
• C. Both basal and reticular
• D. None of the above

Answer: (B)

Laminin is a key glycoprotein that helps epithelial cells attach to their underlying support. It is most abundant in the basal lamina, the thin layer directly beneath epithelial cells, where it forms networks with other components like type IV collagen to create a scaffold that anchors the cells and supports cell behavior. The reticular lamina lies below the basal lamina and is produced by the connective tissue; it is richer in reticular fibers (type III collagen) and other connective tissue components, not laminin. So, laminin is best thought of as a major component of the basal lamina, the layer in contact with the epithelium, whereas the reticular lamina serves as the connective tissue side of the basement membrane.