In an isotonic solution, the flow of water in and out of the cell is happening at the same rate. Water moves into and out of cells by osmosis. If a cell is in a hypertonic solution, the solution has a lower water concentration than the cell cytosol, and water moves out of the cell until both solutions are isotonic.

If a cell is placed in an isotonic solution, there will be no net flow of water into or out of the cell, and the cell’s volume will remain stable. If the solute concentration outside the cell is the same as inside the cell, and the solutes cannot cross the membrane, then that solution is isotonic to the cell.

Mechanism. Osmosis is the movement of a solvent across a semipermeable membrane toward a higher concentration of solute (lower concentration of solvent). In biological systems, the solvent is typically water, but osmosis can occur in other liquids, supercritical liquids, and even gases.

A cell in an isotonic solution is in equilibrium with its surroundings, meaning the solute concentrations inside and outside are the same (iso means equal in Latin). Water molecules do freely move in and out of the cell, however, and the rate of movement is the same in both directions.

A hypertonic solution is one which has a higher solute concentration than another solution. An example of a hypertonic solution is the interior of a red blood cell compared with the solute concentration of fresh water.

Seawater. Seawater has a high amount of salt particles compared to freshwater, making it a hypertonic solution. Freshwater fish can’t live in seawater because the water would rush from their cells into the surrounding saltwater. They would soon die from dehydration.

Examples of when hypertonic solutions are used include to replace electrolytes (as in hyponatremia), to treat hypotonic dehydration, and to treat certain types of shock. Solutions with a lower concentration of solutes than isotonic solutions are hypotonic.

Isotonic IV Fluids

• 0.9% NaCl (Normal Saline Solution, NSS)
• Dextrose 5% in Water (D5W)
• Lactated Ringer’s 5% Dextrose in Water (D5LRS)
• Ringer’s Solution.
• Nursing Considerations for Isotonic Solutions.
• 0.45% Sodium Chloride (0.45% NaCl)
• 0.33% Sodium Chloride (0.33% NaCl)
• 0.225% Sodium Chloride (0.225% NaCl)

Hypotonic solution: A solution that contains fewer dissolved particles (such as salt and other electrolytes) than is found in normal cells and blood. Hypotonic solutions are commonly used to give fluids intravenously to hospitalized patients in order to treat or avoid dehydration.

When a hypotonic solution is administered, it puts more water in the serum than is found inside cells. As a result, water moves into the cells, causing them to swell.

Hypotonic Solution Examples Hypotonic saline i.e., 0.45% sodium chloride or 0.25% sodium chloride with or without dextrose, 2.5% dextrose solution, etc are some of the examples of the hypotonic solutions that are hypotonic with respect to blood serum and are used as hypotonic intravenous solutions.

A hypotonic solution has a lower concentration of solutes than another solution. In biology, a solution outside of a cell is called hypotonic if it has a lower concentration of solutes relative to the cytosol. Due to osmotic pressure, water diffuses into the cell, and the cell often appears turgid, or bloated.

Salt in that example would be a hypertonic solution.

A hypotonic solution is any solution that has a lower osmotic pressure than another solution. When the concentration of solute in one solution is lower than that in the other, than it is said to hypotonic solution.

Isotonic solution: A solution that has the same salt concentration as cells and blood. Isotonic solutions are commonly used as intravenously infused fluids in hospitalized patients.

The purpose of an isotonic drink is to improve the intake of water, minerals and nutrients to facilitate the replacement of what the body uses during effort. It facilitates rehydration, while contributing to the proper assimilation of the particles needed to support effort (glucose, sodium etc.)

One liter of 0.9% saline has a [Na] (and Cl) of 154 mEq/L so the final osmolality is 308 mOsm. But this is the same osmolality as the water content of the blood. The measured osmolality of blood is lower because there is a 7% solid phase of blood that contains no NaCl. 0.9 saline is thus considered “isotonic”.

As noted above, it’s crucial to use sterile water. Create a saline solution by adding the correct amount of pure, non-iodized sodium chloride to the water, to create one of two solutions: isotonic, which is 0.9% salt and 9 g sodium chloride dissolved in one liter of water.

Solutions that have the same osmotic pressure as that of body fluids are said to be isotonic with the body fluid. Body fluids such as blood and tears have osmotic pressure corresponding to that of 0.9% Nacl or dextrose aqueous solution; thus, a 0.9% Nacl or 5 %, dextrose solution is called as isosmotic or isotonic.

Types of studies hypotonic saline solutions (0.45% NaCl or less, such as 0.18% or 0.3% NaCl) with. isotonic saline solutions (e.g. 0.9% NaCl or Hartmann’s solution).