Which is one of the two major types of matrices associated with collagen?

• A. Basement membrane
• B. Basal lamina
• C. Interstitium
• D. Elastin network

Answer: (C)

Two main extracellular matrices involve collagen: the basement membrane and the interstitial (interstitium) matrix. The interstitium is the fibrous, mesh-like network that fills connective tissue spaces and contains fibrillar collagens such as type I and III, along with proteoglycans and glycoproteins. This arrangement provides tensile strength and a scaffold that supports resident cells. That makes the interstitium one of the two major collagen-associated matrices. The basement membrane, lying beneath epithelial and endothelial layers, is a separate, sheet-like matrix enriched in type IV collagen and laminin (often referred to as the basal lamina as part of the basement membrane). Elastin networks are a different component that confers elasticity and are not the two primary collagen matrices.