Which type of collagen is found in blood vessels and parenchymal cells?

• A. Type II
• B. Type I
• C. Type III
• D. Type IV

Answer: (C)

The key idea is that collagen types have distinct tissue roles. Type III collagen forms thin, highly branched reticular fibers that create a delicate supportive mesh in soft tissues. This reticular network is especially important in organs with many parenchymal cells and in the walls of blood vessels, where it provides flexible scaffolding without adding rigidity. Hence, you’ll find Type III collagen surrounding parenchymal cells and lining vascular structures, giving it that characteristic supportive framework. In contrast, Type I is the main fibrillar collagen in skin, bone, and tendon; Type II is the cartilage collagen; Type IV makes the basement membranes under epithelial and endothelial cells. This combination of location and function makes Type III the best fit for being found in blood vessels and around parenchymal cells.