Synovial membrane

The synovial membrane (also known as synovium or stratum synoviale) is a specialized connective tissue that lines the inner surface of capsules of synovial joints and tendon sheath. It makes direct contact with the synovial fluid lubricant, which it is primarily responsible for maintaining. In contact with the synovial fluid at the tissue surface are many rounded macrophage-like synovial cells (type A) and Fibroblast-like (type B) synovial cells. Type A cells maintains the synovial fluid by removing wear-and-tear debris and type B cells produces hyaluronan among other extracellular components in the synovial fluid.