Final answer:
The percentage of body fluid weight made up by water in the cells, known as the Intracellular Fluid, accounts for approximately 60% of the total body water. This water is vital for cellular function and is regulated to prevent cell damage.
Step-by-step explanation:
The percent of body fluid weight made up by water in the cells, or Intracellular Fluid (ICF), constitutes about 60% of the total body water. In an average adult male, the ICF accounts for roughly 25 liters of fluid. This intracellular water is essential for maintaining the proper function of cells, as it is part of the cytosol or cytoplasm within the cells. The body fluid compartments include both the intracellular fluid and the extracellular fluid, which surrounds all cells and is further divided into plasma and interstitial fluid.
The distribution of water in the body is critical because it participates in various physiological processes and serves in different capacities, such as a medium for chemical reactions and a transporter of nutrients and waste. The balance of water is regulated by processes such as osmosis, ensuring cells neither swell excessively nor dehydrate, maintaining overall cellular integrity and function.