How can isotonic, hypertonic, and hypotonic solutions be differentiated?

• A. By their solute concentrations compared to blood plasma
• B. By their pH levels compared to neutral solutions
• C. By their temperature stability
• D. By their effects on drug absorption rates

Answer: (A)

The differentiation between isotonic, hypertonic, and hypotonic solutions is primarily based on their solute concentrations in relation to blood plasma. An isotonic solution has the same concentration of solutes as blood plasma, which allows for no net movement of water across cell membranes. This is important in medical settings, especially for IV fluids, as it helps maintain cell volume and function.

A hypertonic solution has a higher concentration of solutes compared to blood plasma, leading to water moving out of cells to balance the solute concentrations, which can cause cells to shrink. In contrast, a hypotonic solution has a lower concentration of solutes than the blood plasma, resulting in water moving into the cells, potentially causing them to swell and even burst.

This understanding is critical in pharmacology and medicine, particularly when determining the appropriate type of solution to use when rehydrating or administering IV medications to ensure cellular health and stability.