Body fluids are liquids found within the human body that play essential roles in maintaining health and supporting various physiological functions. These fluids include blood, lymph, interstitial fluid, and cerebrospinal fluid. Each type of fluid has specific functions, such as transporting nutrients, removing waste, and providing lubrication to joints. The composition of body fluids is crucial for homeostasis, which is the body's ability to maintain a stable internal environment. For example, plasma, the liquid component of blood, carries cells and proteins, while synovial fluid lubricates joints. Proper balance and regulation of these fluids are vital for overall health.