While returning from the grocery store, Bob was held at gunpoint by two men who wanted to rob him of his belongings. Bob had never been in a fight before, yet he could feel his heartbeat rapidly rise, along with a sudden urge to fight the two men. This involuntary increase in Bob's heartbeat and his immediate urge to fight the men are controlled by the__________.
sympathetic nervous system: This system directs the involuntary responses of human who faces any perilous and anxiety situation. It is also termed as involuntary nervous system.
