Regulation of Blood Glucose Levels- A Key Example of Negative Feedback in Homeostasis

Homeostasis is related to dynamic physiological processes that help the body maintain a constant internal environment necessary for optimum body functions (Mader & Windelspecht, 2017). In homeostasis, internal variables, including blood pressure and body temperature, are kept within a narrow range necessary for optimal function. If the internal variables change in response to a stimulus, there will be a signal creation, and the body will respond through homeostatic mechanisms. On the other hand, a feedback loop can be defined as a system that controls the levels of an internal variable in which there are identified receptors, control centers, effectors, and communication methods (Mader & Windelspecht, 2017).

Variables are parameters monitored by the feedback loop; the internal receptors will detect any changes in the variable, control centers will compare the variables and signal the effector organs to elicit a response, while effector organs execute changes to adjust the variables (Mader & Windelspecht, 2017). Communication methods occur through hormones or nerves as signaling modes (Mader & Windelspecht, 2017). There are two types of feedback loops: negative and positive. In positive feedback loops, a change in a variable will result in a positive change, such as increased concentration  (Mader & Windelspecht, 2017).). In a negative feedback loop, a change in a variable will lead to a change in the reverse direction (Mader & Windelspecht, 2017).

An example in the body is glucose regulation, which involves a negative feedback loop. Glucagon and insulin ensure blood glucose levels are within a normal range. If glucose concentration gets too high, insulin is secreted into the bloodstream, and this causes the body cells to utilize glucose, lowering the concentration (Ojha et al., 2019). If glucose concentration becomes low, there is the secretion of glucagon, which leads to the release of glucose from body cells, increasing glucose concentration (Ojha et al., 2019).

References

Ojha, A., Ojha, U., Mohammed, R., Chandrashekar, A., & Ojha, H. (2019). Current perspective on the role of insulin and glucagon in the pathogenesis and treatment of type 2 diabetes mellitus. Clinical Pharmacology: Advances and Applications, 11, 57-65. https://doi.org/10.2147/cpaa.s202614

Mader, S., & Windelspecht, M. (2017). Human biology. McGraw-Hill Education.