Advertisement

Excretion and Osmoregulation

  • G. W. Stout
  • N. P. O. Green
Chapter
Part of the Macmillan Master Series book series (MACMMA)

Abstract

  • Excretion The elimination of the waste products of metabolism from an organism.

  • Secretion The passage of useful intracellular molecules into the extra-cellular environment. (This term should not be confused with excretion, which deals with waste substances.)

  • Egestion The elimination of waste substances (mainly undigested food), which have never been involved in cellular metabolic activities.

  • Metabolism The chemical and physical reactions occurring in living organisms.

  • Osmosis The movement of water molecules from a region of their high concentration to a region of their low concentration through a differentially permeable membrane.

  • Hypotonic The state which exists within a solution which contains more water molecules than another solution from which it is separated by a differentially permeable membrane (i.e. a solution with a higher water potential than another solution).

  • Hypertonic The state which exists within a solution which contains less water molecules than another solution from which it is separated by a differentially permeable membrane (i.e. a solution with a lower water potential than another solution).

  • Isotonic The state which exists between two solutions separated by a differentially permeable membrane which have the same water potential (see Chapter 7).

  • Ultra-filtration The process by which water and solute molecules separate from a solution, under pressure, according to their differential abilities to pass through a membrane.

  • Selective reabsorption The selective passage of solute molecules, ions and water through a membrane.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© G. W. Stout and N. P. O. Green 1986

Authors and Affiliations

  • G. W. Stout
  • N. P. O. Green

There are no affiliations available

Personalised recommendations