izotón

Izotón is a term used in chemistry and physics to describe a solution that has the same osmotic pressure as another solution. This means that the concentration of solute particles is effectively the same in both solutions, leading to no net movement of water across a semipermeable membrane separating them. The concept is particularly relevant in biological contexts, where cell membranes act as semipermeable barriers.

When a cell is placed in an isotonic solution, its volume remains stable because the water entering and leaving the cell is balanced. This is in contrast to hypotonic solutions, where the solute concentration outside the cell is lower, causing water to rush in and potentially swell or burst the cell, or hypertonic solutions, where the solute concentration outside is higher, drawing water out and causing the cell to shrink.

Medical applications frequently utilize the principle of isotonic solutions. For instance, intravenous (IV) fluids administered to patients are typically isotonic with blood plasma. Common examples include normal saline (0.9% sodium chloride solution) and Lactated Ringer's solution. These fluids are designed to replenish lost fluids or deliver medications without causing harmful shifts in the body's cellular water balance. The precise concentration of solutes in these medical solutions is carefully controlled to ensure they are isotonic with the body's fluids.