Synovial fluid
Synovial fluid is the thick, slippery fluid inside a joint capsule that lubricates the cartilage surfaces. Because cartilage has no blood supply, it is also the route by which nutrients reach the cartilage cells.
Also called joint fluid, synovia.
It is made by the synovial membrane that lines the joint capsule, and its slipperiness comes largely from hyaluronic acid and lubricating proteins. The surface zone of articular cartilage is in direct contact with it (Sophia Fox 2009).
With no blood vessels in the cartilage, water moving through the tissue helps carry nutrients to the chondrocytes, and compressing the matrix drives that flow (Sophia Fox 2009). The building blocks a chondrocyte uses to make glutathione, cysteine, glycine and glutamate or glutamine, reach the cell by this route too, not from a blood vessel next door.
Sources
- Sophia Fox AJ, Bedi A, Rodeo SA. The basic science of articular cartilage: structure, composition, and function. Sports Health 2009.
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