فسيولوجي

Physiological variation of TBW: q Age: TBW is higher in infant and young children (about 70% ) than adult due to active protoplasm and decrease progressively. lesser in old age (about 52%)so they are seriously affected by dehydration qSex: TBW is lesser in female (about 50% ) than adult due to high fat content in their bodies qBody weight: TBW is lesser in obesevCell contained in watery internal environment – life sustained exchange. vICF ; 40% OF BODY composition (2/3 BW) vECF ; 20% % OF BODY composition (1/3 BW) ISF 15% Plasma 5%•Importance of body water : 1. Water constitutes not less than 40% of TBW of any living organism. 2. Act as a solvent: for digestion, absorption, secretion , exertion, mobility of ions. 3. Water has an ionizing property: Means water can dissociate into OH- and H+ which is very important property in many aspects.Body fluid compartment Normal adult young male weighing 70kg has 60% of his body weight water distributed in two major compartments.