This document discusses body fluid compartments and volume expanders. It begins by outlining the total body water, intracellular fluid, and extracellular fluid compartments in the body. It then discusses the properties of various volume expanders, including crystalloids like saline and colloids like albumin, dextrans, gelatin, hydroxyethyl starch, and polyvinylpyrrolidone. For each type of volume expander, the document provides details on their composition, mechanism of action, advantages, and disadvantages. The document emphasizes that colloids are generally better than crystalloids at expanding plasma volume for longer durations.