Which membrane secretes synovial fluid into the joint space?

The synovial membrane is the specialized connective tissue that lines the inner surface of the joint capsule in synovial joints. Its primary function is to produce synovial fluid, which serves several important roles within the joint space. This fluid lubricates the articulating surfaces of the bones, reducing friction during movement, and it also nourishes the cartilage, provides shock absorption, and helps to maintain the overall health of the joint.

The structure and composition of the synovial membrane are specifically adapted for secretion, making it distinct from other types of membranes like the articular membrane, mucous membrane, or pericardial membrane. Although the articular membrane refers to the cartilage covering the ends of bones within a joint, it is the synovial membrane that is responsible for the production of synovial fluid. The mucous membrane primarily lines organs and body cavities that are exposed to the external environment, while the pericardial membrane surrounds the heart and contains pericardial fluid, but neither of these plays a role in joint lubrication or synovial fluid secretion.