Synovial fluid contains nutrients for the cartilage (which is not vascularised and is provided with nutrition by diffusion) and serves as a joint lubricant. The synovial membrane is normally a one cell layer thin inner cover of the joint capsule. It is well vascularised, but
In synovitis such as in rheumatoid arthritis, synovial fluid may be abundant and clearly detectable on physical examination.
The function of synovial fluid is