Stress Flashcards
(169 cards)
What is General Adaptation Syndrome?
Describes the physiological reaction that occurs in response to stress
Who proposed GAS?
Hans Selye (1936)
What are the three stages of GAS?
Alarm reaction
Resistance
Exhaustion
What happens during alarm reaction?
A threat or stressor recognised
Physiological responses activated in preparation for fight or flight response
Hypothalamus signals sympathetic nervous system, which activates and stimulates the adrenal medulla to secrete adrenaline and noradrenaline
This helps increase heart rate, blood flow and blood sugar levels, resulting in fight or flight response
What happens during resistance?
If stressor continues: body will attempt to adapt to stressful situation
Sympathetic nervous system activity begins to decline,
adrenaline and noradrenaline secretion also declines however it also increases from adrenal cortex
Physiological activity is still greater than normal and uses a lot of energy
Individual may appear to be coping however the body’s resources are being consumed at a harmful rate
In response, parasympathetic nervous system becomes activated to conserve energy for the long term as the stressor becomes chronic
What happens during exhaustion?
As stress continues, body’s resources will becomes depleted and the adrenal gland will not function efficiently, blood sugar levels will drop and physical health will be affected resulting in stress-related illnesses such as high blood pressure, heart disease and ulcers etc.
The immune system may becomes compromised and the individual may become susceptible to other illnesses too
How is GAS supported by research?
Selye initially experimented with rats, subjecting them to various stressors including cold, excessive muscular exercise and even surgical injury. He noticed the same typical collection of responses occurred regardless of the stressor and similar findings were also apparent in humans
This was seen to be a general response by the body that could not be attributed to any specific injury or bodily reaction to damage
The results of these findings supported his ‘doctrine of non-specificity’ and that there was a non-specific response by the body to any demand made upon it
What is a benefit to the development of GAS?
It was the first theory to explain the physiological effects of stress and influenced a lot of later theories, especially into the negative effects of stress upon health
This has led to a number of treatments from medicine to CBT in an effort to manage stressful responses better
What is a limitation to research on GAS?
Most research based on rats
Makes findings difficult to generalise to humans
This is because humans have a greater emotional and cognitive input that can influence the stress response and unlike rats who are more passive in their response to stress, humans generally respond more actively to tackle or lessen stressors
What is a criticism of Selye’s belief that individuals respond in the same way to all stressors?
Not true
Mason (1995)
Showed stressors varied in the amount of adrenaline and cortisol they produced depending on amount of fear or anger created by stressors
There also appeared to be gender differences in the stress reactions as women engaged in the ‘tend and befriend’ response
This would suggest gender bias in the theory and limited application across both genders
What activates the hypothalamic-pituitary adrenal system?
Prolonged and chronic stress
How does the HPA system work?
When hypothalamus activated, sends signal to activate sympathetic nervous system and also produces hormone corticotropin releasing factor (CRF) which is released into bloodstream
CRF stimulates anterior lobe of the pituitary gland which causes release of adrenocorticotropic hormone (ACTH) into bloodstream
ACTH travels to the adrenal glands located just above kidneys, which triggers release of stress-related hormones (most important being cortisol)
What is cortisol?
Stress hormone
Some cortisols function helps the body to cope with a stressor, e.g., cortisol is a glucocorticoid hormone which permits a steady supply of blood sugar which provides individual with constant source of energy that is used to deal with stressors
Release of cortisol increases capability to tolerate more pain than normal as well as leads to impaired cognitive ability and reduced immune system performance
What is the Sympathomedullary Pathway?
The sympathetic nervous system and sympathetic adrenal medullary system make up the sympathomedullary pathway
Consists of the parts of the body involved in the immediate response to acute stressors
What do acute stressors activate?
Autonomic nervous system
What are the two branches of the autonomic nervous system?
Sympathetic nervous system
Parasympathetic nervous system
What is the sympathetic nervous system?
‘Troubleshooter’
Highly responsive to stimuli
Once activated, responsible for emotional states and heightened arousal
What is the parasympathetic nervous system?
‘Housekeeper’
Responsible for maintaining equilibrium and calming bodily processes.
What happens when an individual is exposed to an acute stressor?
SNS is activated and simultaneously the sympathomedullary pathway stimulates the release of adrenaline in the bloodstream from the adrenal glands
Adrenaline prepares the body for the ‘fight-or-flight’ response by boosting supply of oxygen and glucose to the brain and muscles while suppressing non-emergency processes such as digestion
Once the stressor is no longer apparent, the parasympathetic system activates and the physiological arousal associated with the fight or flight response begins to decrease
Evaluate why research into short and long-term stressors and their effects has limitations
Complicated due to gender differences
Most research relies on male animals because female hormones fluctuate due to ovulation and this confounds results
Means that conclusions drawn from earlier research into stress may reflect a male bias
Research by Taylor et al (2000) suggests the female response to stress tends to be different from a general fight or flight response, engaging in a tend and befriend strategy
During the environment of evolutionary adaptiveness in our evolutionary past, this behaviour would have involved protecting themselves and their young through nurturing behaviours and forming protective alliances with other women
It is therefore possible that women have a completely different response to stress given their responses evolved in the context of being primary caregivers to children
Some animal studies using rats suggests a physiological response that inhibits the fight or flight response which involves the release of the hormone oxytocin
This increases relaxation, reduces fearfulness and decreases the physiological characteristics of the fight or flight response
This would ultimately mean that the standard description of the SAM and HPA and gender-based theories
What is a criticism of physiological responses?
They ignore psychological factors, such as cognitive appraisal
Lazarus (1999) argues that people make appraisals of stressors by actively working out whether it is a threat (primary appraisal) and whether they have the resources to cope with it (secondary appraisal)
Additional support for cognitive factors - Speisman et al (1964)
Asked students to watch a primitive and gruesome medical procedure while their heart rates were measured
Changes to the heart rate were observed dependent on how they observed the procedure and when it was seen to be traumatic, heart rate increased while perception of the procedure being a joyful rite of passage, heart rates decreased
This would implicate a cognitive element which the purely physiological explanations cannot account for as it shows humans are not passive in the face of stressors as physiological theories assume
How does chronic stress affect the immune system?
Continuous production of corticosteroids will interfere with leucocyte activity and the production of antibodies
Stressful events have also been linked to certain illnesses such as cancer, chronic fatigue disorder and even infections such as influenza
Too much cortisol can suppress the immune system resulting in harming the things that protect us from infection
What did Kiecolt-Glaser et al do?
Investigated effects of stress on the immune system
Describe procedure of how Kiecolt-Glaser investigate the effects of stress on the immune system?
Studied medical students due to sit exams
75 medical students gave blood samples twice, one month before exam period and another sample on day of first exam
Students also completed medical questionnaires measuring their sources of stress and self-reported psychological symptoms