Basal Mechanisms of Water and Salt Homeostasis

Abstract

More than 100 years ago Claude Bernard pointed out that it is body fluids washing all the cells in an organism rather than the atmosphere surrounding the body that represents the environment all mammals (including man) live in. He therefore termed the extracellular fluid “the internal milieu” which is perfectly isolated from, and protected against, erratic oscillations of the external inanimate world thanks to a number of homeostatic mechanisms. The maintenance of a steady relationship of water and solutes (principally sodium chloride) is just one example of such homeostatic mechanisms.