The physiology of stress

The physiology of stress

“The greatest weapon against stress is our ability to choose one thought over another”
(William James)

Stress is not a modern invention

This quote from William James (1842–1910), a lead American thinker, philosopher and psychologist, makes it clear that stress is an old phenomenon and one we all want to combat. “Why pooing your pants is not the only option” is a series of blogs that journeys deeper into the phenomenon we call stress. First we kick off with stress’s physiology – why, when stressed, some of us run to the toilet whilst others turn to figs or anti-constipation powders. Blogs two and three illuminate the link between stress, our environment and our health. And blog four talks about stress alleviation techniques.

Prevalence and effects

Contemporary statistics published by the Mental Health Foundation tell us about how people experience stress today. Four thousand six hundred and nineteen people took part in a poll undertaken by YouGov in 2018: of those who took part, 74% reported feeling overwhelmed by stress, which had an effect on their eating, drinking and smoking behaviour. They also said they felt depressed and anxious; some had suicidal thoughts, and many felt lonely.

While we need to be vigilant that such polls might be most participated in by those who feel most affected by stress, nonetheless, it does seem clear that stress can affect our psychological and physiological health.

But why so?

To answer this question, we now dive into the physiology of stress, as this can make us aware of which aspects of stress are unchangeable and which aspects we can, and possibly even should, work with.

Physiological process of stress

When we encounter stress, we are facing a form of threat. Regardless of how sophisticated we believe we are, our body reacts to it. Our automatic nervous system – in particular, our sympathetic nervous system – kicks in. The physiology of stress is acting upon our brain, heart, our blood and internal organs.

Our brain:

The amygdala is a set of neurons, deeply embedded in each temporal lobe of our brain. One function this area has is the detection of threat or stress. The hypothalamus, a small brain region close to the pituitary gland and part of the so-called limbic system, is what triggers the release of two hormones important to our bodily stress reaction: adrenaline and cortisol.

Our heart:

Our heart increases its beat and the beat increases in strength in order to pump blood around our body more rapidly.

Our blood:

Withdraws from our skin and our viscera and is directed to bodily systems that are more important when under attack: the muscles and the brain. Our lymphocytes and coagulation system are enhanced which increases our body’s ability to seal and heal wounds as well as combat infections.

Our spleen:

It contracts which enhances our immune system.

Our bronchi:

They dilate and our breathing is deepened so that our oxygen levels increase.

Our liver:

The stored glycogen is transformed, and glucose is released into our system. The energy stored there is available to us.

Our vision:

Our visual efficiency becomes better through the increase of the pupillary status. We also experience an increase in sweating, a decrease in salivation and our gut activity changes. We can image these changes like a gut spasm. When they are local, we can become constipated. When they spread across the gu, we run – to the toilet.

Here we are

Pumped up to the brim with energy and ready to go. Regardless of whether or not you want it, once our brain encounters a threat, it triggers the above reactions. So, what is this reaction in service of? Read on.

Read more about stress and find practical tips:

The physiology of stress

The effects of unused stress

Healthy stress behaviour: fight, flight and freeze

Alleviate stress or why pooing your pants is not the only option


Photo by Photo by Free To Use Sounds on Unsplash