The extracellular fluid compartment is a compartment containing heterogenous collections of fluids and not a continuous fluid phase. The cell membrane actually provides the boundary in between the extracellular and the intracellular compartments. The distribution of body water in different compartments has been presented schematically in Fig. The water of the body can be considered to be distributed within two main compartments-the extracellular and the intracellular. The percentage of water in various tissues and the proportion of total weight of the body which each tissue represents, have been presented in Table 5.3. Besides this, the relative distribution of water in the various organs and tissues is mostly same in man as well as in other species. It has been observed after studying thoroughly the water content of the body in man as well as in different animal species that the total water content in man is similar to that of in other animals. The average water content in different tissues of the body has been presented in Table 5.1. Mitchell and his associates (1945), Wid-dowson and his co-workers (1951) have also determined the water content of the human beings by direct method. In 1863 Bischoff determined the water content of an executed criminal by the method of desiccation. The total body water content can be determined most accurately by the process of desiccation. In general, woman contains more fat than man. In lean person, the value is higher than that of in obese person. But the above values vary mostly with the relative degrees of leanness and fatness of the individual. In human being it is about 65% of the body weight in males and about 10% less in females. Report of the Task Group on Reference Manis, admittedly, a bit much for most readers.Total body water in an average human being, weighing about 70 kg is 40 litres to 45 litres. And then they went and did it anyway. It is available for download in its entire 500 page glory, in case you ever need to refer to it for something as granular as the fluid content of a newbortn's thymus, or the normal boron concentration of human hair (0.2-0.8 mg/100 g, by the way). Of man which are known to be important or which are likely to be significant for estimation of dose from sources of radiation within or outside the body", because "however important or desirable it may be to have a Reference Man embodying all known characteristics of man, the task of defining such a Reference Man is clearly beyond the scope of the present effort". This thing was originally intended as an instrument to help scientists calculate dose following radiation exposure, and initially "it was agreed that the Task Group would limit its attention to those characteristics It is rarely referenced (because why would you), but if you dig around you will find that most of these textbooks get their information from the extensive and fascinating Report of the Task Group on Reference Man, by Snyder et al (1974). This material should seem very familiar it appears in the first chapters of almost every physiology textbook, often as a series of stacked bar graphs describing the body composition of the Ideal 70kg Person. communicates with the intracellular fluid, rather than the interstitial fluid.Transcellular fluid: ~1.5% (1050ml) fluid formed by the secretory activity of cells, Intracellular Fluid = 33% ( 23.1 litres) this volume is regulated by the movement of free water.Įxtracellular Fluid = 27% (18.9 litres) this volume is regulated by the movement of sodium. Higher in obesity, but as a lower proportion of body mass, as adipose tissue is only 10-20% water.Total body water: 42 L (60% of total body mass)
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