Which membrane is responsible for producing synovial fluid?

Which membrane is responsible for producing synovial fluid?

• A. Synovial membrane
• B. Periosteum
• C. Endosteum
• D. Fibrous capsule

Answer: (A)

Producing synovial fluid happens in the synovial membrane, which lines the inner surface of the joint capsule. Its specialized cells, called synoviocytes, secrete a slippery, viscous fluid into the joint cavity. This fluid lubricates the joint, reduces friction between the moving ends of bones, and nourishes the avascular cartilage. The other structures have different roles: the periosteum covers the outer surface of bone, the endosteum lines the inner bone surfaces, and the fibrous capsule is the tough outer layer that provides stability but does not itself produce synovial fluid (the synovial membrane sits on its inner surface).

Producing synovial fluid happens in the synovial membrane, which lines the inner surface of the joint capsule. Its specialized cells, called synoviocytes, secrete a slippery, viscous fluid into the joint cavity. This fluid lubricates the joint, reduces friction between the moving ends of bones, and nourishes the avascular cartilage.

The other structures have different roles: the periosteum covers the outer surface of bone, the endosteum lines the inner bone surfaces, and the fibrous capsule is the tough outer layer that provides stability but does not itself produce synovial fluid (the synovial membrane sits on its inner surface).