What effect does a decrease in extracellular osmolarity have on cells?

A decrease in extracellular osmolarity leads to an osmotic gradient where the concentration of solutes outside the cells is lower compared to the inside. Cells primarily consist of water and various solutes, and when the surrounding fluid has a lower osmolarity, water moves into the cells through osmosis.

As water enters the cells, the internal pressure increases, causing the cells to swell. If the osmotic change is significant and rapid, there is a risk of the cells bursting due to the excessive volume of water that has entered. However, the immediate effect of decreased extracellular osmolarity is the swelling of cells as they attempt to equilibrate their internal environment with the lower external solute concentration.

This osmotic behavior is fundamental in understanding how cells interact with their environment and the importance of maintaining proper osmotic balance to prevent cellular damage.