Fight or flight response

The endocrine system and the ANS often work together.

For example, when a person perceives a situation as stressful, their hypothalamus triggers the pituitary gland & the sympathetic branch of the ANS is triggered.

The ANS changes from its normal resting state (parasympathetic) to the physiologically aroused state (sympathetic)

The stress hormone adrenaline is released in response, leading to physiological changes (increased heart rate, sweating etc) which creates the physiological arousal necessary for the fight or flight response.

Once the perceived stressor passes, the ‘parasympathetic’ branch of the ANS returns the body to normal, reducing the effects and activity of the sympathetic branch.