Ace Your NESTOR Session 91 Exam 1 Practice 2026 – Dive Into Success!

The fight-or-flight response is produced by the sympathetic branch of the autonomic nervous system. When a threat is detected, the sympathetic system ramps up arousal to prepare the body for action: heart rate and respiration increase, pupils dilate, airways open, blood is redirected to muscles, and glucose is released for quick energy, while nonessential functions like digestion are momentarily reduced. This rapid, automatic activation is what enables you to either confront or escape danger. The central nervous system is the broad network of brain and spinal cord that coordinates all functions, but the specific system responsible for this quick mobilization is the sympathetic division. The parasympathetic division does the opposite—calming the body and promoting rest and digestion after the threat passes. The somatic nervous system governs voluntary muscle control, not this automatic arousal.