When a system falls out of homeostasis, your body will react withhormones, enzymes, and other substances to correct this imbalance. A negative feedback loop effectively “puts the brakes” on the reaction once homeostasis is achieved and systems are stabilized.
This article illustrates how a negative feedback loop works. It offers examples to help you understand what’s involved in achieving and maintaining biological homeostasis.
How Negative Feedback Loops Work
Imagine that the body is a factory making Product X, and imagine that making too much of Product X is expensive, wasteful, and harmful. This means that the body needs a way to slow down the factory when enough Product X has been made.
It does this through a negative feedback loop. What that means is that the speed of production is sensitive to the amount of Product X. When it starts to build up, production slows.
It might help to think of the factory as a great, big assembly line that stocks shelves at the end. When the shelves get full, the assembly line has to slow down since there’s nowhere to put the product. Too much product building up can cause damage.
However, if the shelves are empty, there’s plenty of space on which to stock the product. The assembly line can speed up until the shelves are full again, with the goal of keeping the shelves filled at the right level all the time.
The opposite of this would be a positive feedback loop. In that case, the more Product X there is, the faster the plant will make more.
What Is a Positive Feedback Loop?
A positive feedback loop is when the product of a reaction leads to an increase in that reaction.
Examples of Negative Feedback Loops
To understand negative feedback loops, it’s important to understand homeostasis, or the body’s tendency toward stability. Homeostasis is very important in the human body. Many systems have to self regulate for the body to stay in optimal ranges for health.
Negative feedback loops regulate and maintain different functions in the body to keep the systems in balance. Examples include:
Menstrual Cycle
Thefemale menstrual cycleoperates through a negative feedback loop that involves various structures in the brain:
Hormones and Your Menstrual Cycle
Blood Glucose
Glucose(sugar) is the body’s main source of energy. In humans, a blood glucose level of 4 grams, or roughly one teaspoon, is essential for normal function.
Vaginal Acidity
Another negative feedback loop regulates vaginal acidity. The body needs to keep the acidity within a narrow range to prevent disease-causing microorganisms from invading vaginal tissues and to prevent the overgrowth of bacteria and yeast naturally found in thevaginal flora.
Conditions likebacterial vaginosis, in which “good” and “harmful” bacteria are imbalanced, can disrupt the vaginal pH and trigger positive and negative feedback responses:
5 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Fagerlund R, Behar M, Fortmann KT, Lin E, Vargas JD, Hoffman A.Anatomy of a negative feedback loop: the case of IκBα.J R Soc Interface.2015 Sep 6;12(110):20150262. doi:10.1098/rsif.2015.0262Walter MH, Abele H, Plappert CF.The role of oxytocin and the effect of stress during childbirth: Neurobiological basics and implications for mother and child.Frontiers in Endocrinology. 2021;12. doi:10.3389/fendo.2021.742236Moenter SM, Silveira MA, Wang L, Adams C.Central aspects of systemic estradiol negative and positive feedback on the reproductive neuroendocrine system.J Neuroendocrinol.2020 Jan;32(1):e12724. doi:10.1111/jne.12724Bich L, Mossio M, Soto AM.Glycemia regulation: from feedback loops to organizational closure.Front Physiol.2020;11:69. doi:10.3389/fphys.2020.00069Amabebe E, Anumba DOC.The vaginal microenvironment: the physiologic role oflactobacilli.Front Med (Lausanne).2018;5:181. doi:10.3389/fmed.2018.00181
5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Fagerlund R, Behar M, Fortmann KT, Lin E, Vargas JD, Hoffman A.Anatomy of a negative feedback loop: the case of IκBα.J R Soc Interface.2015 Sep 6;12(110):20150262. doi:10.1098/rsif.2015.0262Walter MH, Abele H, Plappert CF.The role of oxytocin and the effect of stress during childbirth: Neurobiological basics and implications for mother and child.Frontiers in Endocrinology. 2021;12. doi:10.3389/fendo.2021.742236Moenter SM, Silveira MA, Wang L, Adams C.Central aspects of systemic estradiol negative and positive feedback on the reproductive neuroendocrine system.J Neuroendocrinol.2020 Jan;32(1):e12724. doi:10.1111/jne.12724Bich L, Mossio M, Soto AM.Glycemia regulation: from feedback loops to organizational closure.Front Physiol.2020;11:69. doi:10.3389/fphys.2020.00069Amabebe E, Anumba DOC.The vaginal microenvironment: the physiologic role oflactobacilli.Front Med (Lausanne).2018;5:181. doi:10.3389/fmed.2018.00181
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Fagerlund R, Behar M, Fortmann KT, Lin E, Vargas JD, Hoffman A.Anatomy of a negative feedback loop: the case of IκBα.J R Soc Interface.2015 Sep 6;12(110):20150262. doi:10.1098/rsif.2015.0262Walter MH, Abele H, Plappert CF.The role of oxytocin and the effect of stress during childbirth: Neurobiological basics and implications for mother and child.Frontiers in Endocrinology. 2021;12. doi:10.3389/fendo.2021.742236Moenter SM, Silveira MA, Wang L, Adams C.Central aspects of systemic estradiol negative and positive feedback on the reproductive neuroendocrine system.J Neuroendocrinol.2020 Jan;32(1):e12724. doi:10.1111/jne.12724Bich L, Mossio M, Soto AM.Glycemia regulation: from feedback loops to organizational closure.Front Physiol.2020;11:69. doi:10.3389/fphys.2020.00069Amabebe E, Anumba DOC.The vaginal microenvironment: the physiologic role oflactobacilli.Front Med (Lausanne).2018;5:181. doi:10.3389/fmed.2018.00181
Fagerlund R, Behar M, Fortmann KT, Lin E, Vargas JD, Hoffman A.Anatomy of a negative feedback loop: the case of IκBα.J R Soc Interface.2015 Sep 6;12(110):20150262. doi:10.1098/rsif.2015.0262
Walter MH, Abele H, Plappert CF.The role of oxytocin and the effect of stress during childbirth: Neurobiological basics and implications for mother and child.Frontiers in Endocrinology. 2021;12. doi:10.3389/fendo.2021.742236
Moenter SM, Silveira MA, Wang L, Adams C.Central aspects of systemic estradiol negative and positive feedback on the reproductive neuroendocrine system.J Neuroendocrinol.2020 Jan;32(1):e12724. doi:10.1111/jne.12724
Bich L, Mossio M, Soto AM.Glycemia regulation: from feedback loops to organizational closure.Front Physiol.2020;11:69. doi:10.3389/fphys.2020.00069
Amabebe E, Anumba DOC.The vaginal microenvironment: the physiologic role oflactobacilli.Front Med (Lausanne).2018;5:181. doi:10.3389/fmed.2018.00181
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