Brodsky, William A. Mount Sinai School of Medicine, City University of New York, New York, New York.
Schilb, T. P. Mount Sinai School of Medicine, City University of New York, New York, New York.
Last reviewed:April 2019
Show previous versions
- Biological mechanisms
- Transport processes
- Active transport
- ATP systems
- Ion-pair transport
- Membrane permeability
- Mechanisms of water transport
- Related Primary Literature
- Additional Reading
Physiological mechanisms for the maintenance of an optimal and constant level of osmotic activity of the fluid within and around cells. Osmoregulatory mechanisms maintain the internal balance between water and dissolved materials in a biological cell or organism under a variety of environmental conditions, enabling osmotic pressure to be adjusted in relation to the surrounding fluid. (Note that osmosis is the selective passage of solvent molecules through a semipermeable membrane from a dilute solution to a more concentrated one.) The mechanisms of osmoregulation are necessary because practically all living cells function in a fluid environment. Isolated unicellular forms, such as paramecia and amebas, are subject to osmoregulatory mechanisms, as are cells that make up tissues in air-breathing terrestrial animals. Thus, the ionic composition and osmotic activity of extracellular fluids have biological significance with respect to survival of the living cells. The fluid environment of simple unicellular forms of life consists of the oceans, lakes, or streams in which the forms are found, whereas that of complex animal forms consists of the fluid media enclosed by the various compartments of the body. In general, osmoregulatory mechanisms are considered to be most favorable for the initiation and maintenance of vital reactions in the cell and for maximal survival and efficient functioning of the entire organism (Fig. 1). See also: Cell (biology); Cell biology; Ion transport; Osmosis; Physiological ecology (animal); Water
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Contributors include more than 10,000 highly qualified scientists and 46 Nobel Prize winners.
MORE THAN 8700 articles covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 19,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information