Surgery | Basic Science | Importance of Homeostatic Control

Importance of Homeostatic Control
Session Overview
Description
Maintenance of homeostasis, the constancy of the internal environment, is essential for the continuation of life. In this session some fundamental concepts are introduced and the key closely controlled physiological parameters are identified.

Learning Objectives
By the end of this session you will be able to:

• Explain the meaning of the term homeostasis and its importance for the continuation of life
• Describe the cellular consequences of homeostatic failure particularly in relation to tissue ischaemia
• Define the key aspects of cellular function which determine the resting potential across cell membranes

People are able to live in a wide range of external environments but in order to survive their constituent cells must be provided with a constant internal environment. This was recognised by the 19th Century French physiologist Claude Bernard (Fig 1), and he referred to it as the 'milieu interieur'.

A multitude of negative feedback control mechanisms are primarily responsible for the regulation of the cellular environment. These processes are collectively referred to as homeostatic mechanisms. To explore homeostasis we must first recognise the intrinsic gross variability amongst individuals and how this is dealt with in textbooks.