Which term describes a solution with higher osmolality than body fluids?

• A. Isotonic
• B. Hypotonic
• C. Hypertonic
• D. Dialytic

Answer: (C)

A solution with higher osmolality than body fluids is hypertonic. Osmolality measures how many solute particles are in a solution. When a hypertonic solution surrounds cells, its greater solute concentration outside the cells draws water out of the cells to balance the concentrations. That makes the cells shrink. In contrast, isotonic solutions have about the same osmolality as body fluids, so water movement is balanced and there’s no net change in cell size; hypotonic solutions have lower osmolality and cause water to move into cells, making them swell. Dialytic refers to the dialysis process itself and isn’t about osmolality relative to body fluids.