Final answer:
The claim that intracellular fluids make up about 50% of body weight is false; they actually constitute approximately 60% of the human body's total water content and vary depending on an individual's body fat.
Step-by-step explanation:
The statement that intracellular fluids constitute about 50% of body weight is false. Intracellular fluid (ICF) actually makes up about 60 percent of the total water in the human body. This fluid is a major component of the cytosol/cytoplasm within cells.
In lean individuals, intracellular fluid can approach 50% of body weight, but this percentage will be lower in obese individuals due to the inverse relationship of water to fat content. Conversely, extracellular fluid (ECF) represents about 20% of body weight, within which 15% is interstitial fluid and 5% is in blood plasma. Other fluids like cerebrospinal fluid (CSF), ocular fluid, lymph, and synovial fluids make up smaller volumes of the extracellular compartment.