Stress and the Autonomic Nervous System "Fight or Flight"

The Three Stages of Stress Accumulation

Stress Management Stages

Stress and the Autonomic Nervous System "Fight or Flight"
September 1999 - Carol Young

In his book: Stress and the hidden Adversary (1982) C.R. Dobson found 300 printed definitions of stress in his research on existing material. Stress has been described by some as over or lack of stimuli. Figure 1 shows that in order to have health and well being in our lives, we must have the correct amount of stress or stimulus that is right for us as individuals. Too little can lead to depression, lethargy, feelings of being devalued and lack of focus. Conversely, too much stress can lead to exhaustion "burn out" or even "nervous breakdown".


For some people stress is simply the individual's response to an outside stimulus or "stressor" this is known as the environmental perspective some commonly described stressors are;
v Illness
v Trauma (physical and / or psychological )
v Danger (perceived or real)
v Excessive heat or cold
v Excessive sensory stimulation, e.g. noise
v Pain
Many people have produced tables or scales of stressors placing events in order of severity. Usually the top of the list is death of a partner. Marks are given for each event and added up to test the stress an individual is potentially under from the varying stressors.

Stress can also be described as positive, negative, or neutral. Examples of positive stress could be; J Going on holiday,
J Preparing for wanted guests,
J Starting a new job.
J Attending a job interview
J Meeting new people
J Starting a course in anything

Negative stress could be;
L Dealing with illness
L bad news,
L breaking down in the car on a busy / deserted road,
L losing a much needed / wanted job
L Working when tired
L Not having money for a bill

Neutral stress might be many ordinary expected events all happening at the same time, e.g.
K The phone rings,
K The baby cries,
K There's someone at the door,
K The oven timer goes off,
K The potatoes boil over etc.

Because we are all unique individuals our reactions to situations differ. Many people feel this is to do with the following;
v Our upbringing,
v Experience of past events and their outcomes,
v knowledge / information received,
v The support available to us,
v Our own judgement of the situation,
v Our personal perception regarding our ability, or otherwise, to cope.

This is known as The Interactionist Perspective it was developed by Cox (1978), who saw stress as a mismatch between
1. Demand : an internal or external stimulus which is a product of our own value system and expectations and,
2. Coping : the response, which may be felt by us to be satisfactory or unsatisfactory and which effects our future interpretation of the demand.
This is demonstrated in figure 2 below


So, how does stress arise? By looking at two people starting a day in very different ways we may be able to gain some insight into how stress may arise. We will look at person A and person B as the alarm goes off to start the day.

Person A Has had 7 hours of uninterrupted sleep, gets up, showers. Does some simple stretching exercises, relaxation and meditation for an hour in peace and quiet. Eats breakfast. Gets ready for work, has a loving hug and walks to work.

Person B Has only had 2 hours sleep due to noisy neighbours / ill partner / children. Gets up, showers. Prepares breakfast for the household and packed lunches. Finds clothes, books etc. for family members. Drops members of family and maybe friends at various destinations. Cannot find a parking space and so is late for work again.

Person A is more likely to feel loved and loving, calm, relaxed, balanced, physically strong and ready for the day ahead. We could say that person A is in a state of low stress or is balanced.

Person B is more likely to feel undervalued, unloved. unloving, agitated, physically weak and not ready for the day ahead. We could say that person B is in a state of high stress or is unbalanced.

We all have a limited capacity for dealing with stress, some reach their capacity before others. Some people appear to "thrive on stress" but when we look at the physiology of stress can this really be true?

"Fight or Flight"
The autonomic nervous system functions automatically and below the level of consciousness to control such functions such as heart beat, breathing, digestion, pupil size, amount of blood in the arteries, etc. It has two parts, the sympathetic and parasympathetic they act in opposition to one another to create balance between energising the body for activity and calming the body for relaxation. It consists of nerves and ganglia (a ganglion is a group of nerve bodies situated along the course of a nerve). The largest ganglia is the solar plexus, situated just below the diaphragm, this links the central nervous system with organs in the body.

When a person feels threatened in any way the body prepares for "fight or flight" i.e. the body prepares to give the individual extra energy, oxygen, improved vision, better blood supply to muscles by slowing down non-essential activity, increased awareness of all senses. This is so that the person can physically fight off the attack or run away.

However in most societies today many situations do not require us to physically fight or to run away. Our ancestors needed this in order to face physical danger, in most situations we do not. The process is triggered by our emotional response to a situation or by our higher senses i.e. smell, taste, touch / sensation, sight, hearing and the thoughts and judgements we attach to the stimulus. The nerve cells of the sympathetic nervous system in the hypothalamus and the medulla oblongata (in the brain) are stimulated. The hypothalamus increases secretion of adrenocorticotrophic hormone releasing factor (ACTH-RF) into the blood stream. This is received by the pituitary gland and stimulates increased production and secretion of adrenocorticotrophic hormone (ACTH) into the blood stream. When this reaches the cortex of the adrenal glands (situated on top of the kidneys) growth and activity of the cells increase the secretion of glucocorticoid hormones, primarily hydrocortisone (cortisol) into the blood stream. At the same time adrenaline is secreted from the medulla of the adrenal glands into the blood stream.

Together, increased sympathetic nervous activity, increased secretion of glucocorticoids and increased secretion of adrenaline bring about the following physical responses:
u The metabolism speeds up releasing nutrients, including glucose, there is an increase in
    cholesterol in the blood stream.
u Heart rate increases to provide more blood
u Respiration increases, promoting oxygen supply to the tissues and the removal of carbon dioxide
u The supply of blood to and from the tissues is increased
u Blood is redistributed away from non-essential, inactive organs such as skin and gut to
    essential active organs such as the heart and skeletal muscles
u The activity of the gut decreases
u The pupils dilate so that more light can enter the eye.
u Blood coagulability increases to enable speedy coagulation should injury occur
u Inflammation is repressed so decreases resistance to infection
u The central nervous system is aroused so that the person can "learn" or adapt quickly

In the above state the body is ready to physically deal with any threat, and if a fight took place, or the individual ran at speed for some distance, the above responses would be used to the maximum benefit of the body and recovery to homeostasis ( the natural balanced status of the body) would be rapid and smooth. We will now look at the parasympathetic nervous system and it's role in maintaining homeostasis.

What happens when we relax?
The Hypothalamus responds to the amount of adrenaline and glucocorticoids in the blood stream and, by negative feedback on the anterior pituitary, controls the levels. So as the threat diminishes so do the levels of hormones. However if the stressor is continuous as in the frustration and anger of someone who feels powerless and wronged, or someone who is worrying continuously, then the levels are kept high and the parasympathetic system cannot do it's job.

When we relax the parasympathetic system has an opportunity to function fully. The hormones activated by the sympathetic are deactivated by the parasympathetic, and so the system slows down body processes except those that are suppressed by the sympathetic i.e. the digestive system, the skin functions.
The following changes occur when a person totally relaxes;
u Blood to the heart and skeletal muscles decreases and is redistributed to inactive
    organs such as the gut and skin
u Metabolism slows
u Respiration slows
u Pupils constrict
u Digestion speeds up
u Blood coagulation time is lengthened
u The inflammation response is restored ---- immune system
u The central nervous system is taken out of the arousal state

Our societies set norms of behaviour and standards to which some individuals perceive they are expected to adhere. In this competitive atmosphere of increased activity, and the accumulation of wealth and consumer goods, the wellbeing of the individual can be completely over looked.

Lowering standards of living and simplifying life is not something that individuals are encouraged to do. Gaining material wealth becomes a priority that distracts the individual mind away from simplicity and whole health. As we look at the comparative effect of the two systems on the body it is apparent that both are equally important to our survival. It is ironic that the very physiological process that saved many of our ancestors is now killing and disabling many in society today. The importance of relaxation in our society is vital to health and well being and body "ease". A body in a constant state of arousal eventually becomes exhausted and "dis-eased".

The digestive system is unable to do it's job and people suffer from heart burn, stomach and duodenal ulcers, constipation, haemorrhoids, irritable bowel syndrome, ulcerative colitis etc etc. The thickened blood with extra cholesterol and overworked heart leads to heart disease stroke heart attacks and blood clots. People are more vulnerable to infection, the healing process is prolonged, and cancer increases all the time.

Knowing what is happening to our bodies can greatly improve our awareness of the harm that occurs when we ignore our need to switch off the "fight or flight" response and regain balance.

Steve Holland (1991) Managing Care, Pack16, Stress in Nursing. Distance Learning Centre South Bank Polytechnic
P.M. Minett (1980) A Concise Human Biology and Hygiene. Mills and Boon LTD.
McNaught and Callander (1983) Nurses Illustrated Physiology. Churchill Livingstone
Ross and Wilson(1981) Foundations of Anatomy and Physiology. Churchill Livingstone.

The Three Stages of Stress Accumulation (top)

1. Mobilising energy
We switch this on automatically when we need an extra boost in order to do something demanding. This stage gives us a real "high". We feel that we can move mountains.
J We speed up
J We do everything faster; eating , drinking, talking, walking etc.
J We act more quickly
J We think faster
This stage is easily turned off, with no after effects. If it is not turned off it may lead to stage two.

2. Consuming energy
Demanding extra energy continuously without the body returning to normal. This stage can be draining. We feel pressured into doing things and that there is no escape
K We feel tense most of the time as if being driven
K We become aware of time and external pressures
K We have difficulty with sleep
K We find things to "comfort" us, alcohol, food, cigarettes etc.
K We experience physical symptoms, heartburn, constipation, tiredness, irritability, headaches, back pain, digestion problems, our sense of humour declines, we are less caring, etc. The sign that stage two has been going on too long are when the above symptoms become regular instead of occasional.

3. Draining Energy Stores
This is the stage of strain -- physical, emotional and mental.
We feel exhausted and flat, everything is too much effort
We have "burned out" all our supply of energy without taking time to replenish. There is little or no enjoyment in life at this stage.
There are many physical symptoms
L Recurrent headaches
L Frequent use of antacids and other drugs
L Palpitations, heartburn, stomach cramps, trembling,
L Catching infections and being ill frequently There are intellectual and emotional symptoms
L Loss of concentration and memory
L Inability to reach decisions, think things through
L Active love and caring have lessened or disappeared
L Tears frequently near for no apparent reason
L Dwelling on things in a negative way

Stress Management Stages (top)

1. Becoming aware of who we are at this time; Getting to know ourselves
2. Identifying strengths and weaknesses; Finding out what is useful and what is not so useful.
3. Moving toward who we want to be; Making changes
4. Acknowledging the slow nature of the process; Being kind and patient to ourselves
5. Feeling the joy of being true to ourselves; Being happy and content with who we are.