describe how reset and positive feedback systems create usef

describe how reset and positive feedback systems create useful change .

Solution

Each system has a specific method that it\'s going to use to maintain homeostasis. Many molecular and physiological processes are controlled by feedback mechanisms. In a feedback loop the product of a process, such as the breakdown of proteins into amino acids, has an effect on the rate of the process. Feedback is defined as the information gained about a reaction to a product, which will allow the modification of the product. Feedback loops are therefore the process whereby a change to the system results in an alarm which will trigger a certain result. This result will either increase the change to the system or reduce it to bring the system back to normal Biological systems operate on a mechanism of inputs and outputs, each caused by and causing a certain event. A feedback loop is a biological occurrence wherein the output of a system amplifies the system (positive feedback) or inhibits the system (negative feedback). Feedback loops are important because they allow living organisms to maintain homeostasis.

Positive feedbacks don\'t occur in very many locations. But we will see this in the female reproductive tract, for instance, where we will have an instance where the cell is going to have an endocrine cell secreting a hormone called follicle stimulating hormone, which acts on the target cell to increase the receptors for follicle stimulating hormone on that target cell. So all of these follicle stimulating hormone receptors then increase in number, making the target cell very, very sensitive to the FSH. So that\'s one way to have a positive feedback,

Positive feedback occurs when the rate of a process increases as the concentration of the product increases. The rate of a process will continuously accelerate under positive feedback as long as substrate is available and the product is not consumed by some other process.

Positive feedback enhances or accelerates output created by an activated stimulus. Platelet aggregation and accumulation in response to injury is an example of positive feedback. A feedback loop in which the output of a system is increased by the mechanism\'s own influence on the system that creates that output.

This process can be beneficial but is rarely used because it may become uncontrollable. A positive feedback example is blood platelet accumulation and aggregation, which in turn causes blood clotting in response to an injury of the blood vessels.

And in most cases the response eliminates the stimulus and under those conditions this would be called a negative reflex loop.

The growth hormone raises the blood glucose level by having a signal coming from the empty stomach, which is another hormone called ghrelin, and it turns on this secretion of growth hormone. The growth hormone raises blood glucose, and then cortisol also, it comes on and raises blood glucose further. And this very high blood glucose level actually turns off the growth hormone signal. So growth hormone is regulated by low, it\'s turned on by low blood glucose, and it\'s turned off by high blood glucose levels. So these circadian rhythms occur without us thinking about it

By balancing our inputs and outputs to the body and among the organ systems we can have stability of our internal variable

The change in the variable is corrected by bringing the body back to the initial set point. However, the set points can be reset, and this is an important point. We can reset them, when we\'re resetting out circadian rhythms. But we can also reset them to tolerate higher sodium within the body. Or to tolerate lower temperatures, or to tolerate lower blood pressures or higher blood pressures. So these set points, then, are modified. it\'s important to remember that it\'s not always possible to maintain everything relatively constant.