Physiology of Danger

Courage consists not in blindly overlooking danger, but in seeing it, and conquering it. - Jean Paul

When you perceive danger, your body responds instantly with a series of chemical and muscular changes.


Your eyes are the first to respond to danger. When the eyes see a threat, the pupils dilate, letting more light in to give a clearer view of the threat.


The brain's hypothalamus initiates the body's fight-or-flight response by simultaneously activating both the sympathetic nervous system (which triggers the nerves) and the adrenal-cortical system (which dumps hormones into the bloodstream). The action of the sympathetic nervous system causes the body to become tense and very alert. Meanwhile, the hypothalamus alerts the pituitary gland to activate the adrenal-cortical system, which releases about 30 different hormones to prepare the body to handle the threat. All maintenance stops, digestion stops, everything not needed to get you through the next few seconds stops.


The hormones released into the body during a danger response cause the following physical reactions:


  • Increase in heart rate and blood pressure allowing more oxygen to reach the muscles.

  • Bronchioles in the lungs widen to allow more oxygen to generate more energy as well.

  • Dilated pupils, your vision may narrow (sometimes called "tunnel vision").

  • Your hearing may become more sensitive.

  • Constriction of veins in the skin, which causes the chilly sensation often associated with fear.

  • The liver will release glucose, the bodys main energy source.

  • Tensing of muscles and goose bumps.

  • Relaxation of smooth muscles.

  • You may begin to sweat.

Scared people will often turn pale. During an emergency, less blood flows through the skin and more blood is directed to vital parts of the body that need it, such as the heart and muscles.


Once the threat diminishes, the body releases the hormone cortisol to calm itself back down to normal. The entire fight-or-flight cycle is part of a defense mechanism that has developed over thousands of years.


Stages of Conflict:


1. Arousal - The sniff of a threat creates a surge of adrenaline.

2. Anticipation - The body prepares for fight or flight, the former resulting in testosterone production.

3. Display - The display stage (i.e finger-pointing), is designed to make the threat stand down. Low levels of serotonin have been found to precede violent actions.

4. Threat - Neither individual backs down, creating a situation of severe menace.

5. Attack - The confrontation begins its physical stage.

6. Violence - A surge of endorphins are released.

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