osmolarity

(noun)

The osmotic concentration of a solution, normally expressed as osmoles of solute per litre of solution.

Related Terms

Examples of osmolarity in the following topics:

  • Tonicity

    • A solution's tonicity often directly correlates with the osmolarity of the solution.
    • Osmolarity describes the total solute concentration of the solution.
    • A solution with low osmolarity has a greater number of water molecules relative to the number of solute particles; a solution with high osmolarity has fewer water molecules with respect to solute particles.
    • In a situation in which solutions of two different osmolarities are separated by a membrane permeable to water, though not to the solute, water will move from the side of the membrane with lower osmolarity (and more water) to the side with higher osmolarity (and less water).
    • Three terms—hypotonic, isotonic, and hypertonic—are used to relate the osmolarity of a cell to the osmolarity of the extracellular fluid that contains the cells .

  • Contractile Vacuoles in Microorganisms

    • One cycle takes several seconds, depending on the species and the environment's osmolarity.
    • The amount of water expelled from the cell and the rate of contraction are related to the osmolarity of the environment.

  • Hormonal Regulation of the Excretory System

    • Dehydration or physiological stress can cause an increase of osmolarity above threshold levels, which, in turn, raises ADH secretion and water retention, causing an increase in blood pressure.
    • The water is reabsorbed into the capillaries, lowering blood osmolarity back toward normal.
    • As blood osmolarity decreases, a negative feedback mechanism reduces osmoreceptor activity in the hypothalamus; ADH secretion is reduced.

  • Concept of Osmolality and Milliequivalent

    • Osmolarity is related to osmolality, but is affected by changes in water content, as well as temperature and pressure.

  • Kidney Function and Physiology

    • Kidneys' osmolarity of body fluids is maintained at 300 milliosmole (mOsm).
    • Osmolarity is given in units of milliosmoles per liter (mOsm/L).

  • Introduction to Osmoregulation

    • Osmoconformers are marine animals which, in contrast to osmoregulators, maintain the osmolarity of their body fluids such that it is always equal to the surrounding seawater.
    • They maintain internal solute concentrations within their bodies at a level equal to the osmolarity of the surrounding medium.