osmotic balance

Examples of osmotic balance in the following topics:

• Osmoregulators and Osmoconformers

  • 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 ).
  • The fish do not drink much water and balance electrolytes by passing dilute urine while actively taking up salts through the gills.
  • Sharks are "ureotelic" animals that secrete urea to maintain osmotic balance.
  • Salmon physiology responds to freshwater and seawater to maintain osmotic balance

• Other Hormonal Controls for Osmoregulation

  • The renin-angiotensin-aldosterone system (RAAS) is a hormone system that regulates blood pressure and water (fluid) balance .
  • Mineralocorticoids are hormones synthesized by the adrenal cortex that affect osmotic balance.
  • As sodium is always reabsorbed by active transport and water follows sodium to maintain osmotic balance, aldosterone manages not only sodium levels, but also the water levels in body fluids.
  • ANP affects salt release; because water passively follows salt to maintain osmotic balance, it also has a diuretic effect.

• 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

• Introduction to Osmoregulation

  • Osmoregulation balances concentrations of solutes and water across semi-permeable membranes, maintaining homeostasis.
  • This amount is necessary for the proper balance of electrolytes in the human body.
  • Osmoregulation is the process of maintenance of salt and water balance (osmotic balance) across membranes within the body's fluids, which are composed of water plus electrolytes and non-electrolytes.
  • Both electrolytes and non-electrolytes contribute to the osmotic balance.
  • The process of excretion helps the body maintain osmotic balance.

• Nonthermophilic Crenarchaeota

  • Special chlorine pumps allow the organisms to retain chloride to maintain osmotic balance with the salinity of their habitat.

• 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.

• 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 the tendency for fluid to leak from the capillaries.
  • Describe hydrostatic pressure and osmotic pressure, the factors of capillary dynamics

• Developmental Changes in Fluids

  • The balance of body fluids that are crucial for good health begins during fetal development.
  • The hypothalamic-neurohypophysial system plays a fundamental role in the maintenance of body fluid homeostasis by secreting arginine vasopressin (AVP) and oxytocin (OT) in response to a variety of signals, including osmotic and non-osmotic stimuli.
  • Overview of the renin-angiotensin system that regulates blood pressure and water (fluid) balance.

• Movement of Fluid Among Compartments

  • The osmotic pressure drives water back into the vessels.
  • The balance between the two forces differs at different points on the capillaries.
  • At the arterial end of a vessel, the hydrostatic pressure is greater than the osmotic pressure, so the net movement favors water and other solutes being passed into the tissue fluid.
  • At the venous end, the osmotic pressure is greater, so the net movement favors substances being passed back into the capillary.