👉 Muscle fluid, also known as synovial fluid in joints but similar to muscle fluid in muscles, is a clear, viscous liquid that acts as a lubricant and shock absorber within the body's muscular system. It fills the spaces between muscle fibers, tendons, and other connective tissues, reducing friction during movement and protecting these structures from wear and tear. Produced by specialized cells called synovial cells, muscle fluid maintains the health of joints and muscles by providing nutrients and removing waste products. Its composition includes water, proteins, electrolytes, and hyaluronic acid, which contribute to its lubricating and protective properties, ensuring smooth and efficient muscle function.