osmotic diuresis

Examples of osmotic diuresis in the following topics:

• Glucosuria

  • Glycosuria leads to excessive water loss into the urine with resultant dehydration, a process called osmotic diuresis.

• Diuretics

  • A diuretic (colloquially called a water pill) is any drug that elevates the rate of bodily urine excretion (diuresis).
  • A diuretic provides a means of forced diuresis which elevates the rate of urination.
  • That is, the reduction in blood pressure is not due to decreased blood volume resulting from increased urine production, but occurs through other mechanisms and at lower doses than that required to produce diuresis.
  • Indapamide was specifically designed with this in mind, and has a larger therapeutic window for hypertension (without pronounced diuresis) than most other diuretics.
  • High ceiling diuretics may cause a substantial diuresis – up to 20% of the filtered load of NaCl (salt) and water.

• Osmotic Pressure

  • The osmotic pressure is the pressure required to achieve osmotic equilibrium.
  • The osmotic pressure (II) of an ideal solution can be approximated by the Morse equation:
  • We can see from this equation that the amount of solute present in the solution will directly affect the osmotic pressure of the system.
  • What is the osmotic pressure of a 1.35 M solution of NaCl at 25 oC?
  • Discuss the effects of a solute on the osmotic pressure of a solution

• Osmoregulators and Osmoconformers

  • Persons lost at sea without any fresh water to drink are at risk of severe dehydration because the human body cannot adapt to drinking seawater, which is hypertonic (having higher osmotic pressure) in comparison to body fluids.
  • These fish are incapable of osmotic regulation in the alternate habitat.
  • In relatively hypotonic (low osmotic pressure) fresh water, their skin absorbs water (see [a] in ).
  • Sharks are "ureotelic" animals that secrete urea to maintain osmotic balance.
  • Salmon physiology responds to freshwater and seawater to maintain osmotic balance

• Osmotic Pressure

  • The correct osmotic pressure in the culture medium is essential for the survival of the cells.
  • Osmoregulation is the homeostasis mechanism of an organism to reach balance in osmotic pressure.
  • Having the correct osmotic pressure in the culture medium is essential.

• Capillary Dynamics

  • Hydrostatic and osmotic pressure are opposing factors that drive capillary dynamics.
  • Oncotic, or colloid osmotic, pressure is a form of osmotic pressure exerted by proteins in the blood plasma or interstitial fluid.
  • However, because large plasma proteins, especially albumin, cannot easily cross through the capillary walls, their effect on the osmotic pressure of the capillary interiors will, to some extent, balance out the tendency for fluid to leak out of the capillaries.
  • Describe hydrostatic pressure and osmotic pressure: the factors of capillary dynamics

• Introduction to Osmoregulation

  • Osmosis is the diffusion of water across a membrane in response to osmotic pressure caused by an imbalance of molecules on either side of the membrane.
  • Both electrolytes and non-electrolytes contribute to the osmotic balance.
  • The process of excretion helps the body maintain osmotic balance.
  • Water movement due to osmotic pressure across membranes may change the volume of these fluid compartments.
  • Because blood plasma is one of the fluid components, osmotic pressure can directly influence blood pressure and other medical indicators.

• Plasma and Serum

  • Plasma consists of 90 percent water along with various substances required for maintaining the body's pH, osmotic load, and for protecting the body.
  • Other components in the serum include proteins, which assist with maintaining pH and osmotic balance while giving viscosity to the blood; antibodies, or specialized proteins that are important for defense against viruses and bacteria; lipids, including cholesterol, which are transported in the serum; and various other substances including nutrients, hormones, metabolic waste, and external substances, such as drugs, viruses, and bacteria.
  • Albumin, which constitutes about one-half of the blood serum protein, transports hormones and fatty acids, buffers pH, and maintains osmotic pressures.

• Malpighian Tubules of Insects

  • They are lined with microvilli for reabsorption and maintenance of osmotic balance.
  • The secretion of ions alters the osmotic pressure, which draws water, electrolytes, and nitrogenous waste (uric acid) into the tubules.
  • Explain how insects use malpighian tubules to excrete wastes and maintain osmotic balance

• Hantavirus

  • The diuretic phase is characterized by excessive urination (diuresis) of up to six liters per day, and can last for a couple of days up to a week.