Which system creates biochemical changes to prepare to respond to threat (fight or flight)?

Which system creates biochemical changes to prepare to respond to threat (fight or flight)?

• A. Sympathetic nervous system
• B. Parasympathetic nervous system
• C. Central nervous system
• D. Somatic nervous system

Answer: (A)

When a threat is perceived, the body kicks into the fight-or-flight mode. This is driven by the sympathetic division of the autonomic nervous system. It triggers biochemical changes everywhere in the body—releasing adrenaline and other catecholamines, increasing heart rate and blood pressure, widening airways, and releasing glucose for quick energy—so you’re physically ready to act. The parasympathetic system would slow things down rather than ramp them up, so it wouldn’t be responsible for this rapid activation. The central nervous system coordinates signals, but it’s the sympathetic branch that directly creates the broad autonomic arousal. The somatic nervous system handles voluntary movement and isn’t about triggering these automatic biochemical changes in response to threat.

When a threat is perceived, the body kicks into the fight-or-flight mode. This is driven by the sympathetic division of the autonomic nervous system. It triggers biochemical changes everywhere in the body—releasing adrenaline and other catecholamines, increasing heart rate and blood pressure, widening airways, and releasing glucose for quick energy—so you’re physically ready to act. The parasympathetic system would slow things down rather than ramp them up, so it wouldn’t be responsible for this rapid activation. The central nervous system coordinates signals, but it’s the sympathetic branch that directly creates the broad autonomic arousal. The somatic nervous system handles voluntary movement and isn’t about triggering these automatic biochemical changes in response to threat.