Canadian Society for Medical Laboratory Science (CSMLS) Practice Exam

What happens to blood cells placed in a hypertonic solution?

1. Swell and burst

2. Not affected

3. Hemolyze

4. Crenate

The correct answer is: Crenate

When blood cells are placed in a hypertonic solution, they experience a loss of water due to osmosis. In a hypertonic solution, the concentration of solutes outside the cell is greater than that inside the cell. As a result, water moves from the area of lower solute concentration (inside the cell) to the area of higher solute concentration (the external environment) in an attempt to equalize the solute levels. This movement of water out of the cells leads to a decrease in cell volume, causing the cells to shrink and take on a scalloped or notched appearance, a process known as crenation. This cellular response is typical for red blood cells and illustrates the effects of osmotic pressure in various environments. Understanding this concept is essential for laboratory practices, especially when dealing with fluids and blood samples, as it informs how samples should be handled and stored to maintain cellular integrity.