1. Give other examples of disturbances in the internal environment that can act as a stimulus to a feedback mechanism.
The lowering of normal body temperature may be a disturbance in the internal environment that can act as a stimulus to a negative feedback mechanism. When the sensors in the skin and brain tell the hypothalamus that the normal body temperature has decreased, the blood vessels in the skin contract to prevent heat loss. Skeletal muscles are also triggered, thus shivering to produce more body heat. The thyroid glands are also signaled to secrete more thyroid hormone and increase metabolic activities for heat generation.
Bleeding due to wounds may also be a disturbance in the internal environment that can act as a stimulus to a positive feedback system. When the body is triggered by this, it responds by accelerating the clotting process until the clot prevents further loss of blood.