Final answer:
The two methods of measuring tonicity are by comparing the osmolarity of a solution to the cell's cytoplasm or by measuring the specific gravity using a hydrometer. The osmolarity comparison method is more commonly used.
Step-by-step explanation:
There are two methods of measuring tonicity:
- By measuring the osmolarity of a solution and comparing it to that of the cell's cytoplasm. This method involves determining the total solute concentration in a solution to assess whether it is hypotonic, isotonic, or hypertonic relative to the cell.
- Using a physical measurement such as specific gravity with an instrument like a hydrometer.
The most commonly used method for determining tonicity is the first method, which uses osmolarity measurements. Tonicity is of particular importance in medical settings. For example, both normal saline and lactated Ringer's solution are isotonic solutions commonly administered intravenously. Iso-tonicity with body fluids is crucial to prevent cell lysis or crenation due to water movement across cell membranes.