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synovial fluid

anatomy
Also known as: synovia

Quick Summary

Synovial fluid is a viscous liquid secreted by synovial tissue, which lines joints and tendon sheaths. This fluid is crucial for joint health, acting as a lubricant and nutrient source for cartilage.12

Synovial Fluid Composition and Function

Chemically, synovial fluid is a dialyzate of blood plasma, rich in hyaluronic acid. Physically, it is thixotropic, meaning it is both viscous and elastic, with viscosity decreasing and elasticity increasing with fluid motion. This unique property allows it to form lubricant films between moving joint surfaces.3

Synovial Joints

Synovial joints, also known as diarthroses, are characterized by the presence of this fluid within a joint cavity. This fluid plays a vital role in enabling smooth, low-friction movement between articulating bones. Inflammation of the synovial membrane is called synovitis, and when fluid accumulates in the joint cavity, it is known as effusion.34

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