How does a hypertonic solution affect red blood cells?

A hypertonic solution has a higher concentration of solutes compared to the cytoplasm of red blood cells. When red blood cells are placed in a hypertonic environment, water moves out of the cells and into the surrounding solution in an attempt to balance the concentration of solutes on both sides of the cell membrane. This loss of water results in a decrease in cell volume, causing the red blood cells to shrink. This process is known as crenation. Understanding this osmosis principle is crucial in critical care, as it illustrates how fluid shifts can impact cell function and overall physiological balance in patients.