All are diarthrotic. Includes all limb joints; most joints of the body. Distinguished by Articular cartilage; hyaline cartilage and Joint cavity: small potential space. Articular capsule: Outer fibrous capsule of dense irregular tissue and inner synovial membrane of loose connective tissue. Synovial fluid: Viscous slippery filtrate of plasma + hyaluronic acid and it lubricates and nourishes the articular cartilage.