Final answer:
Negative-feedback mechanisms work to maintain homeostasis by reducing excessive responses and keeping variables like blood glucose and body temperature within normal ranges. These loops can increase or decrease the stimulus as necessary, exemplified by glucose regulation through insulin and glucagon release, and by temperature regulation through sweating and shivering.
Step-by-step explanation:
Negative-feedback mechanisms play a crucial role in maintaining homeostasis within the body by responding to changes in physiological variables. For instance, when blood glucose levels rise after a meal, cells in the pancreas release insulin, a hormone that lowers blood glucose. This is a classic example of a negative feedback loop working to minimize changes and keep glucose levels within a normal range. Conversely, when blood glucose levels fall, the pancreas releases glucagon to increase glucose levels, still operating within a negative feedback framework.
Maintaining body temperature is another example of negative feedback in action. If the body's temperature rises above the set point, mechanisms such as sweating kick in to cool the body down. This feedback loop keeps the body's temperature within a tight range, ensuring efficient function.
However, when homeostatic processes are disrupted, it can lead to homeostatic imbalances like diabetes. As the body ages, the efficiency of these control systems may decline, making elderly individuals more susceptible to health issues.