👉 Background fluid, also known as interstitial fluid, is a vital component of the human body's circulatory system. It fills the spaces between cells and within the cavities of organs, making up about 55% of body weight. This fluid facilitates essential processes such as nutrient and waste exchange, maintaining cell volume, and supporting the transport of substances between blood vessels and tissues. It acts as a medium for biochemical reactions, ensuring that cells receive the necessary nutrients and oxygen while efficiently removing metabolic waste products. The composition of background fluid closely mirrors that of plasma, the liquid component of blood, but it is less concentrated and more permeable to molecules, allowing for efficient diffusion across cell membranes.
