From the Guidelines
Negative feedback functions through a self-regulating mechanism that responds to deviations from a set point by initiating changes in the opposite direction of the initial deviation, as seen in endocrine systems where hormones induce significant biological changes at circulating concentrations in the part-per-billion or part-per-trillion range 1. This mechanism is crucial for maintaining homeostasis in biological systems, and it involves various components such as sensors, control centers, and effectors.
- Sensors detect changes in the system variable, such as thermoreceptors detecting changes in body temperature or glucose receptors detecting changes in blood glucose levels.
- Control centers process this information, such as the hypothalamus processing temperature changes or the pancreas processing glucose changes.
- Effectors implement corrective actions, such as sweat glands activating to cool the body down or insulin being secreted to lower blood glucose levels. The actions of hormones are dictated based on the specificity of their interactions with receptors, the concentration of the hormone in the blood, the abundance and location of the receptor, and other factors, highlighting the complexity of negative feedback mechanisms in endocrine systems 1. Negative feedback loops can also involve receptor downregulation, receptor desensitization, receptor competition, and receptor interactions, which are important for preventing excessive fluctuations and keeping vital parameters within ranges compatible with normal function. In the context of hormonal systems, negative feedback is essential for maintaining stable internal environments, and its disruption can lead to various diseases and disorders, emphasizing the importance of understanding and appreciating the role of negative feedback in maintaining homeostasis 1.
From the Research
Mechanism of Negative Feedback
- Negative feedback is a fundamental feature of biological systems, which helps maintain hormonal levels within a relatively narrow range 2.
- This process is crucial for achieving a state of equilibrium or "homeostasis" in the body 2, 3.
- Homeostasis is a dynamic process that enables the organism to adapt to changing environmental conditions by interacting with multiple feedback systems 3.
- Negative feedback loops play a key role in this process, helping to stabilize the internal environment and maintain optimal functioning of the body's systems 2, 3.
- The hypothalamus-pituitary-adrenal axis is an example of a system that uses both positive and negative feedback loops to regulate cortisol levels and maintain homeostasis 2.
- The brain mineralocorticoid and glucocorticoid receptors are essential for mediating feedback effects on cortisol and maintaining homeostasis in this system 2.