The word stress in English originally means "burden voltage". In many languages, including Czech, the word stress has become synonymous with psychological stress at the stage where we do not already uncomfortable - that at the stage of mental exhaustion. In this text I not engaged acute stress. If you are suffering from acute psychological stress, try looking here .
This article is about the concept of stress, inextricably linked with the name of the famous physiologist Janosz / Hans Selye. Selye called the "father of stress" (see caption Battistuzzi2011hsf ) is not quite right - but rather should be called the creator of a unified theory of medicine. That you have a theory of medicine you never heard of? Nothing not worry, this is normal.
Selye benefits - from stress after theoretical medicine
Janosz / Hans Selye Stress led to a general awareness in r. 1936 article "A syndrome produced by diverse nocuous agents" (Nature). Selye later created the theory of nonspecific stress - generalized adaptation syndrome. Selye benefit lies not in the invention of the word stress, but the generalization of observed trials. Selye tried to generalize health, homeostasis, stress load, adaptation ranges etc. and thereby created the foundation of something, what he calls a unified theory of medicine. It is a comprehensive theory as well, such as the theory of evolution in biology (fitness, evolutionary pressure, genetic drift ...) Benefits Selye can hold extol (see Szabo2012lhs ), but the end is that the practice of medicine generally accepted Selye reference only specific experimental results, the concept of stress and stress hormones. Theoretical and medical benefits Selye remained basically unnoticed.
Maybe you've already heard Selye terms eustress and distress. Roughly, eustress with the prefix euro is "good" stress, which activates us and provides superior performance. Distress is a situation where our forces to present sufficient burden - the burden is beyond our adaptive range. Selye ( Selye1950sga , Selye1950ars ...) tied to a specific stress response, which varies according to the nature of the stressor (example: when the heat load on your coat rozepínáme during load turn up cold) and non-specific response, which is always the same and it expresses the concept of generalized adaptation syndrome. It has three phases:
- stage alarm (acute stress reaction)
- stage adaptation
- stage of exhaustion
These three phases nonspecific stress response is characterized by typical physiological changes, whose center is called. Hypothalamic-pituitary axis stress hormones: CRH (brain), ACTH (pituitary), and then adrenal catecholamines (adrenaline, noradrenaline) and corticosteroids (cortisol). While adrenaline (epinephrine) and noradrenaline (norepinephrine) are typical for the first phase of the stress response (fall into cold water, unsuitable arrival of police officer ...), the actual stress hormone cortisol.
Acute stress reaction in Selye effect lasts several hours, during which the individual devotes all his strength to survive, sometimes even at the cost of a particular self. If the load is too large, the organism it after several hours adapts and enters the adaptation phase where although gives an increased amount of energy, but the burden already tolerates without further damage. The level of stress hormones (mainly cortisol) is elevated, but stable, the load is fully compensated. According to the load size and resources of the organism may duration adaptation phase vary widely. Phase exhaustion - according to its title - is characterized by resource depletion organism. The level of stress hormones are increasing again, but the burden is no longer compensated body on its last legs. When the damage reached an irreversible point, death occurs.
Under load many times the adjustment range of the body can exhaustion and death occur immediately, without the adaptation syndrome. Conversely, if the load is bearable in the long term, it takes a long-term adaptation phase and exhaustion does not occur at all. According to the type and degree of the load may or may not lead to a faster wear of organs. For example, a slightly increased physical activity does not harm the body. In contrast, chronic psychological stress (technically called allostatic burden Mcewen2000aal ) damages the body elevated cortisol levels and immune changes , which together with nerve factors may contribute to chronic depression , obesity , and autoimmune diseases .