Which synovial cells make up about 25% of the synovial membrane and have phagocytic activity?

Which synovial cells make up about 25% of the synovial membrane and have phagocytic activity?

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

Answer: (A)

Within the synovial membrane, the macrophage-like synoviocytes are the cells that perform phagocytosis, helping to clean debris from the joint space. They make up about a quarter of the lining cells, which fits the 25% figure in the question. Their role is to patrol the synovial fluid, remove dead cells and debris, and contribute to immune defense in the joint. The other main type, fibroblast-like synoviocytes, lines the surface to produce and maintain the components of synovial fluid, such as hyaluronic acid, rather than engaging in phagocytosis. Classifications beyond these two aren’t standard for the lining and don’t match the phagocytic function described. Therefore, the macrophage-like synoviocytes best fit the description.

Within the synovial membrane, the macrophage-like synoviocytes are the cells that perform phagocytosis, helping to clean debris from the joint space. They make up about a quarter of the lining cells, which fits the 25% figure in the question. Their role is to patrol the synovial fluid, remove dead cells and debris, and contribute to immune defense in the joint. The other main type, fibroblast-like synoviocytes, lines the surface to produce and maintain the components of synovial fluid, such as hyaluronic acid, rather than engaging in phagocytosis. Classifications beyond these two aren’t standard for the lining and don’t match the phagocytic function described. Therefore, the macrophage-like synoviocytes best fit the description.