Final answer:
Feedback mechanisms are critical for homeostasis, with negative feedback loops being more common to stabilize internal conditions. Negative feedback reduces deviations from a set point, such as insulin regulating blood glucose. Positive feedback amplifies changes, such as oxytocin increasing contractions in childbirth.
Step-by-step explanation:
Homeostasis is the ability of an organism to maintain stable internal conditions necessary for survival. Feedback mechanisms are critical to the regulation of this process: they act to maintain homeostasis by adjusting physiological systems in the body. Feedback mechanisms can be either negative or positive, with negative feedback loops being more prevalent in the body.
Negative Feedback
Negative feedback mechanisms work to reduce or dampen the changes that occur in the body, helping to bring a system back to its set point. For example, when blood sugar levels rise, the pancreas secretes insulin, which encourages cells to take up glucose and liver to store glucose as glycogen, consequently decreasing blood glucose levels. This process is a negative feedback because it negates the change (high blood sugar) by bringing it back towards the set point (normal blood sugar levels).
Positive Feedback
In contrast, positive feedback mechanisms amplify or increase the changes, pushing the system further away from its set point. An example is the process of childbirth, where the secretion of oxytocin hormone increases uterine contractions, which in turn results in more oxytocin being released, further increasing contractions. This mechanism is known as positive feedback because it enhances the change happening in the body.