Synovium & Synovial Fluid

The synovium is a connective tissue that lines the inner surface of synovial joints and produces synovial fluid, which provides lubrication and nourishment to cartilage.

The synovial membrane is composed of two layers: an intima and subintima.
It is rich in blood vessels, lymphatics, and type A/B synoviocytes.
Synoviocytes produce hyaluronic acid and lubricin, key components of synovial fluid.
Synovial fluid:
Is ultrafiltrate of plasma enriched with hyaluronan.
Acts as a lubricant and shock absorber.
Supplies oxygen and nutrients to avascular cartilage.
In inflammation (e.g. arthritis), synovial thickening and hyperplasia occur, often accompanied by increased fluid and inflammatory cells.