The Fight or Flight Response

The fight or flight response is an automatic physiological reaction that occurs when the body perceives a threat or danger. It prepares the body to either fight the threat or flee from it. This response evolved to help our ancestors survive physical dangers (e.g. predators) and is controlled by the autonomic nervous system.

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How the Fight or Flight Response Works

When a threat is perceived, the following sequence occurs:

1. Threat Detection

The amygdala (a small structure in the brain involved in processing emotions, especially fear) detects the threat and sends a distress signal to the hypothalamus.

2. Activation of the Sympathetic Nervous System

The hypothalamus activates the sympathetic nervous system (the part of the autonomic nervous system that prepares the body for action). This triggers the adrenal glands to release adrenaline (and noradrenaline) into the bloodstream.

3. Physiological Changes

Adrenaline causes a series of rapid physiological changes: