Bones linked by cartilage, e.g., pubic symphysis. 2 Joint capsule of dense irregular fibrous CT, continuous with the periostea, encloses a joint space for synovial fluid. 3 Nervous joint receptors for proprioception are in the capsule. The cells make lubricating hyaluronic acid and glycoproteins, and determine the nature of the cartilage-sustaining synovial fluid. In arthritis , inflamed synovium threatens articular cartilage.
Synovial cytokines stimulate chondrocytes to emphasize cartilage breakdown over renewal.