Which type of synoviocyte provides nutrition to the joint?

• A. Type B
• B. Type A
• C. Type C
• D. Type D

Answer: (A)

Nourishment for articular cartilage comes from the synovial fluid that bathes the joint, since cartilage itself lacks blood vessels. The two main synoviocyte types have distinct roles: fibroblast-like (secretory) synoviocytes produce the components of synovial fluid, including hyaluronic acid, helping to create and maintain a viscous fluid that delivers nutrients to the cartilage. In contrast, macrophage-like (phagocytic) synoviocytes line the joint surface to clear debris and participate in immune responses, rather than providing nutrition. So, the cell type that supplies nutrients to the joint through synovial fluid is the fibroblast-like synoviocytes. Nonstandard or less clearly defined types don’t primarily contribute to joint nourishment.