What part of the brain is used in sympathetic arousal (ANS)? Solution Answer: During danger or frightening situations, the body responds by increasing the heart rate and raising the respiration rate. These are arousal responses which sets one ready to fight or flee. The sympathetic nervous system is responsible for the arousal responses and prepares the body to respond to such situations. This system works in coordination with the parasympathetic nervous system which calms the body during arousal. The sympathetic and parasympathetic nervous system together forms the autonomic nervous system..