As mentioned in the previous blog, the components of stress are:
Stressor + Perception of Stress = Stress Response
The stress response is what happens within the body when the survival brain neurocepts a threat. As we know, it doesn’t have to be a physical threat and they are often symbolic and psychological stressors, resulting from anticipation. Broadly, our stress response is a huge mobilisation of energy throughout the body to immediately ensure its survival.
When the survival brain neurocepts there is a threat (which will be based on our perception of stress) it first sends messages to the endocrine system to release the hormones required for short-term survival. These hormonal changes are controlled by the hypothalamic-pituitary adrenal (HPA) axis.
The release of hormones happens in two stages. In this blog we will focus on stage 1.
Stage 1
The survival brain tells the adrenal glands to release adrenaline. It’s main role in the stress response is to prepare us for fight or flight. It does this principally by:
raising the heart rate and increasing the amount of blood, and therefore oxygen, that is pumped to the relevant organs and larger muscles. It also does this by moving blood away from other organs not necessarily in the fight or flight response, such as the digestive tract (think about those nauseated feelings or butterflies in our stomach when you are stressed).
telling the body to release more glucose so energy can be rallied for both the physical response and focus and attention for the brain (this is why stress can be good in meeting deadlines or taking exams).
constricting the blood vessels in our skin so that, should we be wounded at any point, we are less likely to bleed out (this is why our palms can get sweaty, our skin can feel cold and clammy and our hair can stand on end). Adrenaline also triggers the release of fibrinogen to help the blood clot.
You can see that this first stage of the stress response is geared towards an initial increase in supplies of energy and oxygen in the areas of the body most involved in the physical acts of fighting and fleeing.
After the initial release of adrenaline, the HPA axis may moderate the initial release of hormones so that it better corresponds with our perception of stress. As part of this, the survival brain reappraises the mind/body system and environment, relevant to our perception of stress. The HPA will dampen the response where the survival brain considers the mind/body system to have the necessary internal or external resources to manage the stressor.
It is therefore important for the survival brain to know that it is capable of defence, in control, powerful and has autonomy when faced with anything perceived to be a threat. Where it does not feel this way, the HPA axis is likely to dial up the stress response. Think of it like when the fire alarm goes off: the area is examined to see if it is a false alarm or the fire has been put out. Where it is, we are left feeling we have managed the situation well, the alarms are reset, our normal days resume and we feel confident in managing situations involving potential fires in the future.
In the next blog I will cover stage 2 of what happens in the body when the stress response is triggered.
If you have any questions, please do reach out!