Why don't human cells burst from osmosis?

Other answers have emphasized the properties and processes maintaining extracellular isotonicity. A stable extracellular environment is critical, so issues related to kidney and liver functions are important. read more

If a red blood cell is placed in water, water enters the cell by osmosis. Because the membrane is quite weak the cell will burst as the volume and therefore the pressure in the cell increases. Red blood cells shrink when placed in concentrated solutions of sugar as water moves out of them by osmosis. read more

When the plant cell is placed in a hypotonic solution , it takes up water by osmosis and starts to swell, but the cell wall prevents it from bursting. The plant cell is said to have become "turgid" i.e. swollen and hard. read more