All homeostatic mechanisms use negative feedback to maintain a constant value (called the set
point). This is the most important point in this topic! Negative feedback means that whenever a
change occurs in a system, this automatically causes a corrective mechanism to start, which
reverses the original change and brings the system back towards the set point (i.e. ‘normal’).
It also means that the bigger the change the bigger the corrective mechanism. Negative feedback
applies to electronic circuits and central heating systems as well as to biological systems. When
your oven gets too hot, the heating switches off; this allows the oven to cool down. Eventually it
will get too cold, when the heating will switch back in, so raising the temperature once again.