Anatomy of body water and electrolytes

摘要: R ECENT studies, principally involving the application of tracer technics to problems in field body water and electrolyte metabolism, make it timely review redefine anatomical concepts [7,2]. Definitions organization fluids are by no means a trivial exercise since they critically influence interpretations such varied studies as metabolic balances, dilution measurements tissue analyses. The purpose this is re-examine some extent revise prevailing content distribution water, sodium, potassium chloride man. Ideas about fluid anatomy have changed greatly last three decades. These ideas been influenced limitations study, well nature particular problem under consideration. Chemical analyses tissues led proposals concerning [3]. early demonstration histological membrane envelopes encasing cell gave impression that could be adequately described two phases, intracellular extracellular. This distinction justified fundamental differences structure these phases [3-71. Furthermore, cellular activity survival depend on maintenance characteristic patterns both extracellular [5]. By extrapolation from whole organism, original hypothesis was amplified so has terms compartments, i.e., plasma, interstitial [5,8]. scheme, if accurate, would possible define composition observations plasma suitable method for measuring total volume constituents [7]. accuracy stratagem based approximate identity fluid. evidence similarity composition, which quite convincing, summarized previously [9,70]. One most promising technical advances study introduction tracers measure exchangeable electrolytes [I]. were designed provide vivo estimates quantities basis clearer understanding their differential physiological functions. prospect defining abnormalities potassium, across membranes man inspired considerable search substance [ 7,77-791. almost exclusively skeletal muscle its use [4-S, 721. Analogous anions, including bromide, thiocyanate, thiosulfate, sulfate ferrocyanide, stable isotopic forms, also used [73-771. saccharides mannitol, sucrose inulin, introduced measurement circumvent objection permeability cells ions 7478,791. There assumptions studies: (1) existed homogeneous state therefore measurable single substance, (2) pathological changes not affect homogeneity phase. now abundant show first more important erroneous [520-291. heterogeneity phase become apparent bone