<P> In Netter's Atlas of Human Physiology, body water is broken down into the following compartments: </P> <Ul> <Li> Intracellular fluid (2 / 3 of body water) is fluid contained within cells . In a 72 - kg body containing 40 litres of fluid, about 25 litres is intracellular, which amounts to 62.5% . Jackson's texts states 70% of body fluid is intracellular . </Li> <Li> Extracellular fluid (1 / 3 of body water) is fluid contained in areas outside of cells . For a 40 - litre body, about 15 litres is extracellular, which amounts to 37.5% . <Ul> <Li> Plasma (1 / 5 of extracellular fluid). Of this 15 litres of extracellular fluid, plasma volume averages 3 litres, or 20% . </Li> <Li> Interstitial fluid (4 / 5 of extracellular fluid) </Li> <Li> Transcellular fluid (a.k.a. "third space," normally ignored in calculations) contained inside organs, such as the gastrointestinal, cerebrospinal, peritoneal, and ocular fluids . </Li> </Ul> </Li> </Ul> <Li> Intracellular fluid (2 / 3 of body water) is fluid contained within cells . In a 72 - kg body containing 40 litres of fluid, about 25 litres is intracellular, which amounts to 62.5% . Jackson's texts states 70% of body fluid is intracellular . </Li> <Li> Extracellular fluid (1 / 3 of body water) is fluid contained in areas outside of cells . For a 40 - litre body, about 15 litres is extracellular, which amounts to 37.5% . <Ul> <Li> Plasma (1 / 5 of extracellular fluid). Of this 15 litres of extracellular fluid, plasma volume averages 3 litres, or 20% . </Li> <Li> Interstitial fluid (4 / 5 of extracellular fluid) </Li> <Li> Transcellular fluid (a.k.a. "third space," normally ignored in calculations) contained inside organs, such as the gastrointestinal, cerebrospinal, peritoneal, and ocular fluids . </Li> </Ul> </Li>

Where is most of the water in the body located