Synovial Membrane

Synovial membrane (Synovium) is soft tissue that lines the non-cartilaginous surfaces within joints. Synovium has two layers.

• Outer layer (subintima) - loose tissue made up of fibrous, fatty tissues
• Inner layer (intima) - sheet of cells thinner than a piece of paper

The synovium is usually extremely thin, often just one cell in thickness. It is meant to coat the moving parts of the joints which rub against each other, and reduce bone to bone friction. Injuries or other forms of arthritis can cause synovitis (inflammation of the synovial membrane).