1) The Alarm Stage – When are body first perceives there’s a problem. ‘Fight or flight’. Heart rate increases, we breathe more quickly, our muscles tense. 2) The Resistance Stage – If our bodies are exposed for a long time, our bodies learn to adapt to the situation. 3) The Exhaustion Stage – After long term exposure to a stressful situation, our bodies cannot cope. We may develop illnesses as a result such as ulcers, high blood pressure, depression etc. These were called ‘diseases of adaptation’. It only offers one type of response to stress, and neglects that the reaction to stress can vary.
The Hypothalamus The hypothalamic-pituitary-adrenal axis is the following series of events after we perceive a stressor. 1) The evaluation of whether something is actually a stressor occurs in the cerebral cortex. 2) When we perceive that there is a stressor in the environment, these higher areas send signals to the hypothalamus which starts two simultaneous actions in the body: a) Signals are sent to the pituitary gland which releases ACTH into the bloodstream. This stimulates the adrenal cortex to release corticosteroids which helps us get energy by converting fat and protein. b) The Autonomic Nervous System is also activated. This stimulates the adrenal medulla to release adrenaline and noradrenalin into the blood stream. This all leads to an increase in heart rate, blood flow and blood pressure.
Survival Value In modern society stressors are more likely to be psychological than physical than physical and are more long term such as the stresses of working at a desk, commuting etc and therefore the physical response is not really needed, but can still be harmful to our bodies. Long-Term Stress Can Affect your Cardiovascular System 1) When you are exposed to a stressor, glucose is released as a form of energy to your blood stream. However, if you exposed to stressors for long periods of time, it will remain in your bloodstream and could lead to a blockage, producing heart attacks or even strokes.
2) Stress can increase heart rate or blood pressure. Over a long time, blood vessels can become much weaker. 3) If blood vessels are much weaker, they can break and this is called a haemorrhage Differences in Personality Might Cause Cardiovascular Problems Williams – anger and cardiovascular disorders Method: A sample of 13 000 participants completed a questionnaire. This asked questions about their feelings of anger. For example, did they ever feel like hitting someone? Results: Those with a high score on the anger questionnaire were more likely to have a heart attack when tested again six years later.
Conclusion: People who get angry more easily have a higher chance of getting a cardiovascular problem. Other factors apart from personality must be included such as diet, their occupations, genetic vulnerability, exercise levels, smoking and the consumption of alcohol. Stress Can Also Effect the Immune System When someone experiences stress over a long period of time, their immune system stops functioning properly. Brady et al – stress and the development of ulcers Method: Monkeys were given electric shocks over periods of time. There were pairs of monkeys. One was the ‘executive’. The ‘executive’ could delay the shocks by pressing level at the correct moment, however, the other one could not.
Results: The executive monkey was developing illness’s such as ulcers and would later die. Conclusion: The stress was weakening their immune system and therefore killing them. Appalling ethics, monkey’s cannot be generalised to humans and we also know that those with little control over their own lives have high levels of stress. The same Immune System Suppression happens in Humans – Kiecolt-Glaser et al, stress and wound healing Method: Small samples of skin were taken from 13 women who cared for relatives with Alzheimer’s disease. A control group also had samples taken.
Results: The carers took an average of nine days more to heal. Conclusion: Long term stress impairs the effectiveness of the immune system to heal. However, the effects could be due to poor diet, lack of sleep and not just the stress they experienced. Sources of Stress Holmes and Rah� looked through several medial patients records and found that many had suffered major life events prior to their illness. A scale was therefore compiled to show the importance of life changes in terms of stress caused.