Activation of the nervous system, a division of the autonomic nervous system, calms the body after an emergency has ended.

The activation of the parasympathetic nervous system, a division of the autonomic nervous system, helps to calm the body after an emergency has ended. This system is responsible for conserving energy and slowing down the heart rate, among other things. It essentially works to bring the body back to its normal, relaxed state.

Here are the steps:

1. An emergency situation triggers the body's fight or flight response, which is controlled by the sympathetic nervous system. This results in increased heart rate, blood pressure, and alertness.

2. Once the emergency has ended, the parasympathetic nervous system is activated.

3. The parasympathetic nervous system works to counteract the effects of the emergency response. It lowers the heart rate and blood pressure, slows the breathing rate, and promotes digestion.

4. As a result, the body returns to its normal, relaxed state.

5. If the parasympathetic nervous system is not able to effectively calm the body after an emergency, this can lead to chronic stress and other health problems.