What is "interstitial fluid"

n. (context physiology English) A solution found in tissue spaces that inundates and moistens cells in multicellular animals.

n. liquid found between the cells of the body that provides much of the liquid environment of the body

Interstitial fluid or tissue fluid is a solution that bathes and surrounds the tissue cells of multicellular animals. It is the main component of the extracellular fluid, which also includes plasma and transcellular fluid. The interstitial fluid is found in the interstices - the spaces between cells (also known as the tissue spaces). On average, a person has about 10 litres (2.4 imperial gallons or ~2.9 US gal) of interstitial fluid (they make up 16% of the total body weight), providing the cells of the body with nutrients and a means of waste removal.