STRESS, GENERAL ADAPTATION SYNDROME.
Stress – is a state of non-specific adaptative mechanisms tension occurring at excessive (superliminal) factors action to organism. Clinical manifestation is complex of structural, functional and biochemical changings receiving the name “general adaptational syndrome”. The term “stress” was described first and introduced in usage by Hans Selie in 1936.
General adaptational syndrome morphological features.
Multiple pathogenic factors action to organism independently on their features and origin gives standard answer which is expressed in morphological triad:
1) suprarenal cortex hypertrophy;
2) thymic-lymphocytic system involution namely thymus and lymphatic nodes atrophy;
3) ulcers and erosions formation in stomach and intestines.
Stages:
1. Anxiety stage:
a) shock substage is characterized by short-termed resistence decreasing to pathogenic factor;
b) contrshock substage – organism resistance first is restored and then is increased.
2) Resistance stage – is characterized by stable and prolonged increasing of organism resistance both to stressogenic factor and to others.
3) Exhaustion stage – appears at very intensive or prolonged pathogenic factor action as well as under adaptational mechanisms functional weakness conditions. It is accompanied by organism resistance reducing to pathogenic influencings.
STRESS-INDUCING AND STRESS-LIMITING SYSTEMS. DISEASES OF ADAPTATION
Adaptation diseases – diseases dominant role in the development of which has excessive stress and so-called stressor injuring mechanisms. Stress at its big intensivity and duration can be transformed from adaptation mechanism to dysadaptation and even pathogenesis mechanism. Adaptation diseases:
1) psycho-somatic diseases:
a) heart ishemic disease;
b) hypertonic disease;
c) stomach and duodenum ulcer disease;
2) substances exchange diseases (diabetes mellitus);
3) allergic and inflammatory diseases:
a) bronchial asthma;
b) rheumatism.
Stress-triggers or stressors:
1) trauma;
2) coldness;
3) pain;
4) emotions (negative ones);
5) bleeding;
6) physical loading;
7) hypoglycaemia;
8) infections.
These stressors cause excitement of the highest nervous regulatory centers and hormones big amount releasing determined by this. Such excitement can be realized through homeostasis disorders.
Stress-realizing processes:
§ activation of hypothalamic-adenohypophyseal system – ACTH, STH, TTH releasing which stimulate (correspondingly) secretion of glucocorticoids, somatomedines, thyroid hormones;
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§ vegetative nervous system activation (sympathetic and parasympathetic) – is accompanied by catecholamines, insuline, glucagons passage to blood;
§ aldosterone-vasopressine system activation which leads to angiotensine, aldosterone, ADH content increasing in blood.
Stress-limiting systems:
1) endogenic opiates;
2) lovely job;
3) active sexual life;
4) joy from life and so on.
Materials for auditory self-work.
4.1.List of study practical tasks necessary to perform at the practical class.
Materials and methods: preparation instruments set, glass cups with Ringer’s solution, adrenaline in concentration 1:10000, microscope, pituitryne, syringe, insuline, glucose 20% solution, eye pipette, subject glass.
Investigation object: pregnant woman urine, white mice, frogs.
Task 1. To investigate adrenaline influence on pupil width
To destroy frog’s spine and brain with zond (probe). They cut carefully both eyes and put them into 2 glass cups with Ringer’s solution. They put the cups under direct bright light – as a result pupils are constricted. Then physiological solution in one cup is changed on physiological solution to which adrenaline in concentration 1:10000 is added. After 20-30 minutes midriasis is begun reaching its maximum after 1,0-1,5 hours. Second eye in Ringer’s solution is used at control.
Task 2. To observe pituitrine action to melanoforme cells
2 frogs are putted in glass can (jan) situated on bright disseminated light (it’s better to put white paper under can and to cover can’s posterior and lateral walls with it). Frogs become lighter on this shade. Before pituitryne injection one observe in posterior leg transparent membrane melanoforme cells (under microscope). The cells are constricted and look like large black cells. Then one frog is injected intraperitoneally by 0,2 ml of “pituitrine P” solution (1 ml of it contains 1,5-3,0 international units). The frog after pituitryne injection is getting dark right in 20 min after injection. Having putted swimming membrane under microscope one can see that melanoforme cells form processes. In 40-50 min after injection melanoforme processes are increased significantly. By this time one can see common frog darkening distinctly.
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