Physiology and the Acute Stress Response – why does our body produce the same response for all stressors?

The body mobilises the sympathetic nervous system, secretes stress hormones and inhibits others in response to a stressor. And whatever the stressor – whether you are too hot, too cold, having an argument, lost a loved one, or running for the bus – we activate the stress response in the same way.

But before we talk the physiology of stress, let’s talk terminology first. A ‘stressor’ is something that throws your body out of allostatic balance and the stress response is your body’s attempt to restore allostasis. Allostasis is a concept grown from homeostasis, which in recent years has been mainly built upon by Dr Bruce McEwan of Rockefeller University.

Homeostasis vs. allostasis

Homeostasis basically says there is a single optimal level, amount or number for any given measure in the body. Also, that you reach this set point through some local regulatory mechanism. Whereas allostasis recognises that any given set point can be regulated in many different ways, each with its own set of consequences.

Homestasis is about amending this little process or that. Allostasis is about the brain coordinating body-wide changes to achieve a result and that includes changes in behaviour.

The generalised stress response

As we have acknowledged, the body mobilises the sympathetic nervous system, the stress response, in the same way, whatever the stressor. As a physiologist this seems strange. Why would the body do the same thing if it were too hot or too cold – surely, as I was taught during all those lectures at university, specific challenges to the body provoke specific responses and adaptations? Warming causes dilation of the blood vessels, chilling causes the opposite – constriction of the vessels and shivering. Being too hot seems a very different physiological challenge to being too cold and logic would tell us the body’s physiological response should be different.

Survival mode

Why should the body have such a generalised stress response regardless of the situation you find yourself in? However, when you think about it, it actually makes sense. If you’re a starving bacteria stressed by food shortage you can go into a dormant state. But if you’re a starving lion, you’re going to have to run after something to make a kill.

For us humans, the core of the stress response is built around the idea that we’re going to have to work like crazy to survive and therefore the muscles need energy, right now, in a usable form, rather than it being stored away. Glucose and the simplest forms of proteins and fats come pouring out of your fat cells and the liver and are delivered to the working muscles that are going to save you. Blood pressure increases, as does heart and breathing rate to help with the increased demand.

Shut down

Another feature of the stress response is that long-term ‘building projects’ all shut down. Why waste energy on physiological processes that are not needed for your immediate survival. Systems such as digestion and reproduction are closed for business – there’s no need for them if you are not going to survive the next few minutes. Immunity, which does do some interesting things during stress, also shuts down.

The story of the stress response is, don’t waste energy on physiological processes that are not important for immediate survival and divert everything that is relevant to help the body stay alive.

Acute stressors move us away from allostasis quickly, and the stress response is about mobilising the troops to get us back to that point. That’s why our body produces the same response, whether you are too hot or too cold, running for the bus or having argument.

For more information about the physiology of stress, why not join Graeme for his next course? Stress – A Modern Day Epidemic will run on 27th June in Wakefield Yorkshire. Book now!

Practice Mindfulness

Heighten your awareness of the moment by focusing intently on an object. Notice a pencil’s shape, color, weight and feel. Or slowly savor a raisin or a piece of chocolate. Mindfulness leads to relaxation.

Play a Few Bars

A number of recent studies have shown that music can do everything from slow heart rate to increase endorphins. Good bets: Bach’s “Air on the G-String,” Beethoven’s Pastorale symphony, Chopin’s Nocturne in G, Handel’s Water Music, or pianist George Winston’s CDs Autumn or December.

  • 1
  • 2

Courses

INTEGRATIVE HEALTH EDUCATION brings together the best health educators from around the world to present a comprehensive programme of training opportunities. Course subjects include gastrointestinal health, parasites, fungus and bacterial infections, energy and emotional healing practices and mindfulness. If there is a subject you’d like to learn more about, but can’t find a course, just let us know.

Mission Statement

Our vision is that health practitioners can develop the skills and knowledge to employ a variety of practical methodologies that safely bridge the gap between conventional Western medicine and holistic healthcare practices.

Through our training courses we aim to give practitioners, whatever their approach to health and wellbeing, the knowledge, skills and tools that will enable them to deliver the best possible approaches to resolve their patients or client’s health challenges.

Contact Us

© Integrative Health Education 2014-2024 | Terms & Conditions | Privacy Policy