Synovial membrane. Coloured Scanning Electron Micrograph (SEM) of the synovial membrane found within a bone joint. The articular capsule of a bone joint has been opened to reveal the synovial membrane or synovium (grey). The synovium contains and secretes synovial fluid which lubricates the articular cartilage of opposing bones easing their movements. At the same time it supplies nutrients and oxygen to the cartilage. Papillae (green) are evaginations of the membrane made up of a core of connective tissue and rich in small blood vessels. The synovium is specialised connective tissue. Magnification: x450 at 6x7cm size. x570 at 4x5"~LANDSCAPE"