• Karen Law

Reacting to threat - Part 1

When human beings and other mammals face an attack, a harmful event or a threat to survival the brain processes this via the amygdala and then the hypothalamus. These are part of the autonomic nervous system. The pituitary gland then secretes a hormone which releases cortisol and adrenaline. These enable the body to fight or run away.

The outward signs of this include:

* An increase in heart rate

* Tunnel vision

* Shaking

* Dilated pupils

* Flushed face

* Dry mouth

* Slowed digestion

* Hearing loss

* Bladder relaxation

The adrenaline released increases strength for flight or flight. Oxygen, nutrients and blood flow is prioritised to the muscles, therefore digestion and urine production slows or stops. And with the brain being ready for action sleep will be prevented.

The autonomic nervous system, which regulates the body's unconscious actions, contains two parts:

* The sympathetic nervous system,which stimulates the body's fight-flight-or-freeze response

* The parasympathetic nervous system, which stimulates the body to do normal things like digestion, rest and reproduction.