A figure is considered an example of a negative feedback system, as opposed to a positive feedback system, because it demonstrates a process where the output counteracts or reverses the initial deviation from a normal state, leading to stability or equilibrium. In a negative feedback system, when a variable deviates from a set point, sensors detect this change and send the information to a control center that activates effectors. These effectors work to bring the variable back to its normal range, thus resisting further deviation and maintaining homeostasis. Once the variable is stabilized, the feedback loop stops or slows down the response. In contrast, a positive feedback system amplifies the initial change, causing the system to move further away from equilibrium, often leading to exponential growth or instability. A classic example of negative feedback is body temperature regulation: if the body temperature rises, the brain triggers mechanisms such as sweating to cool the body down. When the temperature returns to normal, these mechanisms cease. This loop stabilizes the system and prevents extremes. This feedback loop resists change and restores balance rather than amplifying the change.
Therefore, the figure is labeled a negative feedback system because it shows a cycle responding to a deviation by reversing it to maintain stability, unlike a positive feedback system, which would reinforce and amplify the deviation instead.
