* Isotonic: This means the solution has the same concentration of solutes as the inside of the RBC.
* Osmosis: Water moves across cell membranes from areas of high water concentration (low solute concentration) to areas of low water concentration (high solute concentration).
* Equilibrium: In an isotonic solution, the water concentration inside and outside the RBC is the same. This means there is no net movement of water into or out of the cell.
Therefore, RBCs in isotonic saline solution maintain their normal shape and volume.
Contrast this with:
* Hypotonic solution: Lower solute concentration outside the cell. Water moves into the RBC, causing it to swell and potentially burst (hemolysis).
* Hypertonic solution: Higher solute concentration outside the cell. Water moves out of the RBC, causing it to shrink and crenate (develop a spiky appearance).
Isotonic saline solution is important because it:
* Maintains cell integrity: It prevents RBCs from shrinking or swelling, ensuring their proper function.
* Used in medical procedures: It is frequently used in intravenous fluids, blood transfusions, and other medical procedures where it's essential to maintain the volume and function of blood cells.
