Stress Flashcards
G.A.S
General adaptation syndrome- three stages which explain how the body reacts to stress.
Alarm reaction
Once a stressor is perceived the physiological responses of the body are activated in preparation for fight or flight.
Resistance
Where the body attempts to react to the stressor. Physiological activity is higher than normal and so it uses a lot of energy. The body’s resource are consumed at a potentially harmful rate. The parasympathetic nervous system is activated to conserve energy for the longer term because the stress is becoming chronic.
Exhaustion
Adaption fails in this stage as resources are drained. Begin to experience symptoms of sympathetic arousal that appear in the alarm stage. Adrenal glands may become damaged and stress related illnesses are likely.
Acute stress- Sympathetic arousal
When stressed the sympathetic branch of the ANS is activated by the hypothalamus. Sympathetic nerves connect the brain with many organs and the adrenal glands.
Acute stress- Adrenal medulla
Adrenal glands made up of this and the adrenal cortex. Sympathetic arousal stimulates medulla to release adrenaline and noradrenaline into the bloodstream.
Acute stress- Adrenaline and nor adrenaline
Cause the heart to beat faster, muscles to tense and liver converts glycogen into glucose to provide energy to fuel the fight or flight response.
Acute stress- End of response
ANS divided into sympathetic and parasympathetic nervous system. Once a threat is gone the parasympathetic system is activated and physiological arousal decreases. Priority id now for energy conservation.
Chronic stress response
Activated by the hypothalamic pituitary adrenal system and can persist for several hours or longer. Hypothalamus produces a hormone called corticotropin releasing factor, detected by the pituitary gland releasing adrenal corticotropin hormone into the bloodstream. This id detected by the adrenal cortex which releases cortisol in response.
Cortisol
Some functions help in coping with stress e.g. cortisol affects glucose metabolism by restoring and mobilising energy supplies to power the stress response and has other effects that are damaging to the body for instance cortisol suppresses the immune system.
Negative feedback loop
The HPA is self regulating via negative feedback loop. Levels of cortisol are monitored at the pituitary and hypothalamus. High levels of cortisol trigger a reduction in CRF and ACTH resulting in a corresponding reduction in cortisol.
Support for GAS
Style supported with research on rats subjecting them to stressors and found that the same behaviour followed regardless of the stressor. A general response that could not be attributed to any specific injury, he was then able to tack the rats through the resistance and exhaustion stages. Shows that the body’s general response tot a stressor is a physiological reality.
Challenge for GAS
Mason repeated Seyles experiment using Monkeys and found varied responses meaning that the validity of GAS is challenged and it shows that specific stressors may produce specific responses.
Physiological response evaluation- male bias
Evolutionary women not geared toward fight or flight as it left their children venerable. Suggested they use tend and befriend in case of stressors. This means that flight or flight research is not applicable to females and therefore much physiological research is biased towards men.
Physiological response evaluation- Psychological factors ignored
Animal studies ignore psychological factors like cognitive appraisal. Lazaras argues we make appraisals of a stressor by deciding if it is a threat and if we can deal with it or not. Speisman asked students to watch a procedure while their heart rates were measured. Changes depended on their interpretation of whether the procedure was threatening or not. Shows that humans are not as passive when faced with stressors as research assumes.
