Library · Physiology
Negative feedback
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Your body spends the whole day correcting itself. The main way it does this is called negative feedback, and negative here does not mean bad: it means opposite. If a value falls too low, the body raises it. If it climbs too high, the body lowers it. It is a home thermostat: it turns on when the house gets cold and off when it gets warm.
The mechanism proposed to explain it has five parts working in a loop. A sensor, which measures; a set point, which is the value being aimed at; an error detector, which notices the difference between what is measured and what is wanted; a controller, which decides what to do; and an effector, which carries it out.
Many hormones are governed this way. The gland that makes a hormone is sensitive to the concentration of the substance that hormone regulates: if it detects too much, it makes less; if there is too little, it makes more. The result is that the value swings around its set point instead of running away, and that sustained stability is called homeostasis.
In brief
Negative feedback is a response that opposes change: it raises a value when it falls too low and lowers it when it climbs too high.
A home thermostat: it turns on when the house gets cold and off when it gets warm.
One proposed mechanism for homeostasis describes five parts that must work together: sensor, set point, error detector, controller, and effector.
Many hormones are controlled this way: the gland senses the concentration of the substance it regulates and corrects in the opposite direction.
Sources (2)
- National Center for Biotechnology Information, StatPearls PublishingPhysiology, Homeostasis, StatPearlsPublished
- SEER Training Modules, National Cancer InstituteCharacteristics of Hormones, SEER Training Modules
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
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