User:Anthony.Sebastian/Homeostasis/Sebastian Notes/Archive 1

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Referring to animal systems, Walter Cannon, who coined the word homeostasis, defined it as follows:

The coordinated physiological reactions which maintain most of the steady states in the body are so complex, and are so peculiar to the living organism, that it has been suggested (Cannon, 1926) that a specific designation for these states be employed--homeostasis. [1]

Cannon recognized that “living being[s]” function as ‘open’ systems (see Life) with many “relations” with their surroundings — for example through airways, gastrointestinal tract and skin. He noted that the surroundings could perturb the system to move its key components or subsystems to points outside of their relatively stable and optimal ranges of property or function — the “steady states” in his definition. A change in outside temperature, for example, might perturb the stability of admittedly dynamical biochemical processes to the detriment of the organism. The organism reacts to such potentially adverse effects of it surroundings with physiological adjustments that tend to maintain steady-state, i.e., to maintain 'homeostasis'.

This article will explore the concept of homeostasis in an early 21st century biological setting, exemplify ‘homeostatic’ (homeostasis-maintaining) mechanisms, and relate homeostasis to the concepts of cellular and organismic adaptation, growth, development and reproduction.

  1. Cannon WB. (1929) Organization For Physiological Homeostasis. Physiol Rev 9:399-431 Link to Full-Text