What is the name of the fluid found in joints?

The fluid found in joints is called synovial fluid. This viscous substance is secreted by the synovial membrane, which lines the joints and is responsible for lubricating the articular surfaces to reduce friction during joint movement. Synovial fluid also plays a critical role in providing nutrients and removing waste from the cartilage within the joint, which is essential for maintaining joint health. Its composition includes hyaluronic acid and various proteins that contribute to its lubricating properties, making it vital for the proper function and mobility of joints.

Other types of fluids mentioned, such as serous fluid, interstitial fluid, and cerebrospinal fluid, serve different functions in the body. For instance, serous fluid is found in serous cavities and helps reduce friction between organs, while interstitial fluid is found between cells, providing nutrients and waste exchange. Cerebrospinal fluid is primarily involved in cushioning the brain and spinal cord. However, none of these fulfill the specific role that synovial fluid does in the context of joints.