The following information is available about the body fluid volumes of a normal male: total body water, 40 liters; intracellular water, 25 liters; plasma water, 4 liters. The volume of the interstitial water is?

Subtracting the intracellular water from the total body water gives the extracellular water (15 liters). Since the extracellular water exists primarily of the plasma water and the interstitial water, subtracting the plasma water (4 liters) from the extracellular water (15 liters) gives the interstitial water (11 liters). Ref: Barrett K.E., Barman S.M., Boitano S., Brooks H.L. (2012). Chapter 1. General Principles & Energy Production in Medical Physiology. In K.E. Barrett, S.M. Barman, S. Boitano, H.L. Brooks (Eds), Ganong's Review of Medical Physiology, 24e.