For a 70kg man, what is the normal plasma volume and interstitial fluid volume, respectively?

In a typical distribution of body fluids, the plasma volume for an average adult male weighing around 70 kg is generally estimated to be around 3 to 4 liters. This volume can vary based on individual factors such as hydration and body composition, but it is accurate to say it is approximately 3 liters for many calculations.

The interstitial fluid volume, which represents the fluid found in the spaces between cells, typically accounts for a larger volume in the extracellular fluid compartment. For a healthy adult, the interstitial fluid volume can be around 10 to 12 liters or more, depending on the individual's total body water composition.

In this case, choosing the option that provides 3 liters for plasma volume (which aligns with typical physiological values for a 70 kg male) and 12 liters for interstitial fluid volume (a common estimate for the interstitial space) reflects an understanding of normal body fluid distribution. This combination is consistent with physiological data observed in adults, thereby establishing it as the appropriate choice. The other options either adjust the plasma volume to an amount that is slightly less typical or set the interstitial fluid volume to values that do not align with the common clinical and physiological standards.