Why the tissue fluid surrounding human cells must be isotonic?

Answer 1

In a hypotonic solution, the water potential of the environment is higher. Since water travels from areas of high water potential to low water potential, it will flow into the cell faster than it can be removed. The cell, which lacks a pressure-resisting wall, will swell and soon burst.

In a hypertonic solution, it's the opposite. The water potential of the environment is lower, so the water will flow from inside of the cell to outside. The cell will basically shrivel.

Compare this to the final option. In an isotonic solution, the water potential in both the inside of the cell and the surrounding environment is zero. This means that there is no net movement of water, so the cell will neither burst nor shrivel and remain healthy.

Answer 2

In an isotonic solution the level of solvents and solutes are the same inside and outside the cell.

Diffusion is where a solvent eg water - moves from a solution with a high level of solutes to a solution with a low level of solutes.

So in a cell that has lots of 'bits' in it eg salt, etc in comparison to the solution outside, Diffusion will occur causing water to travel out into the surrounding solution - therefore the cell will shrink.

The opposite way round, water will travel into the cell and it will swell - and may burst if it has no cell wall.

Therefore a cell in an isotonic solution will not gain or lose any water and therefore will maintain its shape.

Answer 3

A surrounding tissue fluid that is isotonic (same concentration of solutes as inside the cell) is important to maintain cell volume and prevent osmotic flow of water in or out of the cell, which can disrupt cellular function. An imbalance in solute concentration can cause cells to shrink or swell, leading to potential damage or malfunction.

Answer 4

Because the cell will exploade if the surrounding cells are hypotonic ... and it will shrink if the surrounding cells are hypertonic .