Negative and positive feedback are the factors in a process that drive the system either toward or away from a stable configuration, according to Dictionary.com. One example of a homeostatic process involving negative and positive feedback is the Earth's climate. Homeostasis is the tendency of the system to push back toward a stable state in response to external influences.Continue Reading
Positive and negative feedback are central to an understanding of homeostasis, which About.com describes as one of the unifying principles in the study of biology. Examples include the regulation of the body's temperature, blood pressure and the body's water and electrolyte balance.
Howstuffworks.com describes a mechanical negative-feedback mechanism that was built into early steam engines. The fly-ball governor was a freely rotating set of swing arms with weights attached to their tips and mounted on a threaded post. As steam pressure built up inside the boiler, steam would be forced up the post and cause the arms to swing. As they swung faster, the weighted tips would rise and force open a valve to release steam. This lowered the pressure and brought down the governor's arms, closing the valve again. This is a classic example of negative feedback maintaining a constant pressure. Reversing the effects by closing the valve when the arms rise would be an example of positive feedback in which high pressure induces higher pressure still until the system breaks down.Learn more about Human Anatomy
The three functions of the circulatory system include maintaining normal body temperature, helping the body fight disease and providing the ideal chemical balance for homeostasis. The circulatory system consists of the heart, arteries, veins and blood.Full Answer >
The urinary system sustains homeostasis by eliminating wastes from the body, regulating blood acidity levels and controlling the levels of metabolites and electrolytes in the blood, such as sodium, potassium and calcium. The urinary system also maintains a stable internal environment by assisting the osmoregulation of blood volume and pressure.Full Answer >
Excretion contributes to homeostasis by getting rid of urea, carbon dioxide, excess salts and excess water to maintain a stable body condition. These compounds are filtered from the blood by the kidneys, which then combine them to form urine. The urine is then passed by ureters to the bladder and is eventually excreted from the body through the urethra.Full Answer >
The immune system maintains homeostasis by preventing pathogens from disrupting the body's normal functioning. It achieves this in various ways, including adaptive immunity when the body encounters a new pathogen, innate immunity, secreting acids onto the skin and using mucus membranes to breakdown bacteria.Full Answer >