<P> Interstitial fluid consists of a water solvent containing sugars, salts, fatty acids, amino acids, coenzymes, hormones, neurotransmitters, white blood cells and waste products from the cell . This water solvent accounts for 26% of the water in the human body . </P> <P> The composition of tissue fluid depends upon the exchanges between the cells in the biological tissue and the blood . This means that tissue fluid has a different composition in different tissues and in different areas of the body . </P> <P> Not all of the contents of the blood pass into the tissue fluid, which means that tissue fluid and blood are not the same . Red blood cells and platelets cannot pass through the walls of the capillaries . The resulting mixture that does pass through is, in essence, blood plasma with lower concentration of plasma proteins . Tissue fluid also contains some types of white blood cell, which help combat infection . </P> <P> Once the extracellular fluid collects into small vessels it is considered to be Lymph, and the vessels that carry it back to the blood are called the lymphatic vessels . The lymphatic system returns protein and excess interstitial fluid to the circulation . </P>

The fluid that moves from the interstitial fluid into lymphatic capillaries is called