Negative feedback is the process by which changes occur to bring an organism’s internal environment back to the normal level.
One example of negative feedback in a living organism is the ways humans regulate their blood glucose levels. I will firstly discuss the processes that occur as a result of blood glucose levels being too low. When blood glucose levels are too low the pancreas will detect this and as a result will start to secrete glucagon from the A cells from the islets of langerhans. This glucagon will now flow in the blood stream to the liver. This will trigger the liver to start converting glucagon to glucose by a process called glycoglysis because the glucagon will bind to receptors in the liver starting the response. The glucose will then enter the blood stream thus increasing the blood glucose concentration. This will be detected by the pancreas which will then stop or decrease the secretion of glucagon; this is the negative feedback as now the internal environment has returned to the norm.
The ability of humans being able to control the blood glucose levels is a benefit because many biological and chemical processes in the body need glucose. For example glucose is needed for respiration and active transport.
Now I will discuss the processes that result from our blood glucose levels being too high. First again the pancreas will detect that blood glucose levels are too low and as a result secrete insulin from the B cells of the islets of langerhans. The insulin secreted will cause blood glucose levels to fall because many body cells have glycoprotein receptors on their cell surface membrane and so when insulin binds to a glucose transport cell it causes a change in the tertiary structure and as a result they open and allow more glucose into the cells and so as more glucose is leaving the blood stream and going into the cells where it