The Stress Reaction
When we perceive a stressor, whether it be consciously orÂ subconsciously, real or perceived, physical or psychological theÂ part of the brain that is linked to the hippocampul system makesÂ the decision via another part of the brain as to whether theÂ perceived or real threat needs to be acted upon. Bearing in mindÂ however that the threat can be conscious, unconscious, physicalÂ or even psychological, it is the perception that is important.
If the threat is perceived as such, the Hypothalamus steps in,Â this activates the body in preparation for the fight or flight. TheÂ nerve impulses are stimulated and the autonomic nervous systemÂ is then started up. The hypothalamus is responsible for this andÂ gives us those characteristically fight or flight symptoms. It does thisÂ as it has control over things like temperature control, heart rate,Â blood pressure and other functions associated with the fight orÂ flight. That fight or flight essential to our survival, as it warns us ofÂ dangers to us whether real or perceived so that we may actÂ accordingly.
The hypothalamus also activates the pituitary gland, alsoÂ known as the master gland, which is situated beneath theÂ hypothalamus. This hypothalamus releases corticotrophin which inÂ turn then stimulates the anterior pituitary gland. The anteriorÂ pituitary gland being responsible for the secretion of ACTHÂ (adreocorticotropic hormone), this hormone stimulates theÂ adrenal cortex, which is situated above the kidneys, this thenÂ produces cortisol. When the cortisol is released it does threeÂ things:-
â¢ Inhibits protein synthesis
â¢ Promotes fatty acids
â¢ Stimulates glucose formation
These actions prepare the body for physical action, supplyingÂ those cells with the necessary substances that may be requiredÂ during stressful times, the fight or flight activation.Â At the same time this occurs, the adrenal medulla isÂ stimulated and secretes adrenaline and noradrenalin which areÂ the hormones necessary in the physical reactions to stress. ForÂ example increased heart rate, increase in muscle tone and otherÂ symptoms associated with fight or flight.
With all of this happening the bodies growth hormone isÂ stirred up and making it grow, pumping blood and energy to theÂ major muscle areas ready fort hat fight or flight.Â It then decides on how we discharge that energy, or how weÂ do not discharge it dependant on the factors involved, the latterÂ however being dangerous as it builds up and can get to the pointÂ of burnout.
When the body is stimulated we then decide how the stressorÂ is dealt. If we use physical activity, then the stress may subsideÂ naturally and our bodies return to an equal state, homeostasis. IfÂ we do not deal with it then, we internalise it and it builds up insideÂ us, creating tension until we blow our tops.