Maintaining homeostasis means that conditions are kept stable and relatively constant. Negative feedback is a mechanism used to reverse or minimize changes in a system. In this example, negative feedback is used to keep the body’s glucose and insulin levels stable. Positive feedback is a mechanism that increases changes in a system. A stress response describes the body’s reaction to threats or pressures. Parasympathetic regulation refers to activities of the nervous system, including slowing the heart rate and boosting intestinal activity.