How is total body water distributed by weight in the compartments?

Total body water is typically distributed in the body's compartments based on specific percentages that reflect the weight of water in relation to total body weight. The proportion of total body water can be categorized primarily into intracellular fluid (ICF) and extracellular fluid (ECF).

In adults, the commonly accepted distribution is that approximately 60% of total body weight is made up of water. Out of this 60%, about two-thirds is found within the intracellular compartment (approximately 40% of total body weight), while one-third exists in the extracellular compartment (approximately 20% of total body weight). This extracellular fluid can be further divided into interstitial fluid and plasma.

The understanding of this distribution is crucial in clinical practice, as it helps healthcare professionals manage fluid therapy, assess hydration status, and understand electrolyte balances within various compartments of the body. Hence, the answer reflecting a distribution of 60-40-20 effectively captures the relative proportions in which water is distributed in the body's compartments, making it the correct choice.