CH3 Stress Flashcards
Stress
is a psychological or physiological response to a stressor which is perceived to exceed the ability of the organism to cope.
Distress v Eustress
Distress is a form of stress characterised by a negative psychological state (e.g. hampers performances).
Eustress is a form of stress characterised by a positive psychological state (e.g. enhances performance, enhances memory)
Stressor
Any stimulus/event that produces stress or is perceived as a threat and a challenge to our ability to cope. Is highly subjective.
Internal vs external stressors
- Internal stressors originate from inside the individual
- Psychological: low self esteem, pessimism,
- Physiological: illness, hunger
- External stressors originate from outside the individual
- Psychological: loud noises, extreme temperatures
- Physiological: upcoming assessments, financial difficulties, relationship conflicts, being overworked
Acute vs chronic stress
Acute stress is stress that usually occurs because of a sudden threat that only lasts for a relatively short time.
- Mainly beneficial; release of adrenaline can enhance problem-solving, physical performance
- I.e. exams, starting a new job, deadlines, fire alarm
Chronic stress is stress that continues for a prolonged period of time.
- Generally more detrimental to our health; can be debilitating and overwhelming
- A result of prolonged high levels of cortisol
- I.e. social isolation, ongoing financial issues, overwork, loneliness, grief, long-term unemployment
Stress response
a reaction that involves the physiological and psychological changes that people experience when confronted by a stressor
Acute stress response
- The fight-or-flight-or-freeze response is an automatic/involuntary response to a threat/stressor
- Involves physiological changes produced by the sympathetic nervous system in readiness to confront the threat (i.e. fight), escape (i.e. flight) or keep absolutely still to avoid detection (i.e. freeze).
The two parts of fight or flight reactions
-
Amygdala activates the hypothalamus, which activates the sympathetic nervous system.
- Secretion of adrenaline (or epinephrine) and noradrenaline from the adrenal medulla of the adrenal gland. These stress hormones circulate in the blood, activating various organs such as the heart, lungs, liver and kidneys and boosting other physiological processes that prepare the body for action.
- The hypothalamus also stimulates the pituitary gland → initiates HPA axis
- Release of hormones from cortex (outer layer) of adrenal glands
- Most abundantly released into bloodstream is cortisol
- Increased energy/alertness
Roles of cortisol in chronic stress
- Increase/maintain high glucose/blood sugar level
- Enhance energy, metabolism etc. to keep the body in an alert, elevated energised state
- Suppression of immune system activity
- Anti-inflammatory effect/reduce inflammation by blocking the activity of white blood cells that contribute to inflammation
- Suppress other bodily systems not immediately required to deal with a stressor.
Characteristics of fight or flight responses
- Increased heart rate and blood pressure
- Redistribution of blood supply from the skin and intestines (i.e. internal organs) to the skeletal muscles, giving more energy
- Increased breathing rate as a means to increase oxygen intake and supply
- Increased glucose secretion by the liver which is used as an energy source
- Dilation of the pupils which allows for more light to be taken in
- Suppression of unessential functions (such as digestion and sexual drive) which can be delayed without damage to the organism as a means to conserve energy.
Once the threat has passed, the parasympathetic system calms and restores normal functioning.
Freeze reactions
- Can occur before the body initiates a fight or flight response.
- Is parasympathetic NS dominant.
- Releases cortisol
Characteristics of freeze responses (tonic immobility)
- Orienting response of the head or eyes towards the direction of the threat
- Hypervigilance e.g. being on guard, watchful, or extremely alert
- Halting of vocalisations
- Racing heart slows very significantly
- Blood pressure drops very quickly.
Adaptivity
- A freeze response is considered to have an adaptive value when it contributes to the survival of the organism.
- e.g. prey that remain frozen during a threat are more likely to avoid detection. The frozen state also conserves energy until a predator loses interest. When this occurs, the animal can use the excess energy for escape (i.e. flight).
- Freezing is not adaptive when fear…
- causes a job candidate to freeze during an interview,
- overwhelms a student’s mind during an important exam.
Approach coping strategies
- Involve efforts to confront a stressor and deal directly with it and its effects.
- Looks at causes and a solution that will address the underlying problem, issue or concern and minimise or eliminate its impact.
e.g. stress due to an upcoming exam might involve an approach effort that targets working harder and spending more time studying while maintaining a healthy lifestyle
Avoidance coping strategies
- Involve efforts that evade a stressor and deal indirectly with it and its effects.
e.g. reducing stress of exam by such behaviour as eating more or playing video games
Selye’s General Adaptation Syndrome (GAS)
- The biological model of stress.
- Is non-specific, meaning it is the same irrespective of the type of stressor the organism is exposed to.
- Is identical within all members of a species, in this case rats.
First stage of GAS
The alarm reaction results in a state of intense arousal and is divided into two phases:
- Shock
- Ability to deal with the stressor falls below its normal level. Decrease in body temperature, blood pressure, and muscle tone and loss of fluid from body tissues
- Counter shock
- The sympathetic nervous system is activated and the body’s resistance to the stressor (i.e. ability to cope with stressor) increases.
- Release of adrenaline, noradrenaline, cortisol; initiation of fight and flight reaction as the hormones supply the muscles with more energy for this.
- The sympathetic nervous system is activated and the body’s resistance to the stressor (i.e. ability to cope with stressor) increases.
Second stage of GAS: Resistance
- Ability to cope with the stressor is higher than usual
-
Cortisol continues to be released into the bloodstream at an abnormally high level
- High blood pressure, high glucose secretion (energy supply)
- Shuts down all unnecessary physiological processes
- e.g. immune system suppresses, digestion, growth and sex drive stall, menstruation stops, and the production of testosterone and sperm decreases
- During this stage, individuals may still feel fine and well (i.e. everything appears normal).
Third stage of GAS: Exhaustion
- The body can no longer sustain its resistance and the effects of the stressor can no longer be dealt with.
-
Resources (i.e. glucose) have been depleted, effects of cortisol ‘wear off’ resistance to disease is very weak, and it becomes more vulnerable to physical and mental disorders.
- e.g. Fatigue, sleep disturbances, severe loss of concentration, vulnerability to anxiety attacks, irritability, depressed mood, jumpiness and crying spells.
The Gut-Brain Axis
- Is a bidirectional, multi-faceted communication link between the central (i.e. brain) and enteric (i.e. gut) nervous systems.
- Relays information via the vagal nerve.
Bi-directional means that information goes two ways - they can influence each other.
Bi-directional relationship between the gut and brain
- Stress can disturb the composition of the gut microbiota.
- Disturbance of the gut microbiota can lead to changes in mood-stabilising neurotransmitter production (as gut bacteria help produce dopamine, GABA and serotonin), higher stress levels, cognitive decline and vulnerability to mental health disorders.
Strengths of GAS
- The model highlights the predictable pattern of chronic stress, which can be easily tested in a laboratory.
- The model identifies the role of the endocrine system and its various hormones that are secreted as part of the stress response.
- The model was among the first to suggest that stress can weaken the body’s ability to resist infection.
- It is influential in developing the idea that out body may eventually run out
of resources and become increasingly vulnerable to disease as the stress persists.
- It is influential in developing the idea that out body may eventually run out
- There is research that suggests that the three stages of GAS exist.
Limitations of GAS
- It is a ‘one size fits all’ model (i.e. assumes all individuals have the same response to any kind of stressor) and does not account for individual differences in biological responses to a stressor.
- It does not account for the cognitive aspects of the stress response – what
might be considered a stressful situation and cause a stress response in one person may not in another. - There is evidence to suggest the response may not be non-specific.
- The findings for the GAS model was based on rats then generalised to humans. They are both physiological different organisms (e.g. humans stress responses are more complex + vulnerable)
What are important characteristics of a healthy gut microbiome?
- High levels of microbiota richness (i.e. the number of different species)
- Diversity (i.e. how different they are)
- Stability, resilience and resistance to significant change over time (e.g. the ability to resist disturbance by an antibiotic medication or poor diet) and to recover a stable state.
Manipulating the gut microbiota to reduce stress-related behaviour and HPA axis activation
- Taking probiotics containing ‘good’ strains of bacteria
- Faecal microbiota transplantations
- Specific diets
Explanatory power
refers to how effective a theory is on explaining a certain concept.
Lazarus and Folkman’s Transactional Model of Stress and Coping
- The psychological model of stress
- Proposes that stress involves an encounter (i.e. transaction) between an individual and their external environment, and that a stress response depends upon the individual’s evaluation (i.e. appraisal) of the relevance of the stressor to his or her wellbeing and their ability to cope with it. (IS HIGHLY SUBJECTIVE)
- Proposes that an individual and their environment have an interrelationship – wherein they can influence and interract with one another.
First stage of the Transactional Model
Primary appraisal:
- Encounter between individual and external environment is evaluated as:
- Benign-positive → an initial appraisal of a stimulus as neutral/good, and not causing stress for the individual
- Irrelevant → an initial appraisal of a stimulus as a non-issue for the individual
- Stressful → further appraisal as a harm/loss, threat (i.e. potential to cause damage), challenge (i.e. opportunity for growth)
Second stage of the Transactional Model
- Secondary appraisal (evaluation of resource availability):
- If resources < demands = stress
- If there are enough resources available → emotion-focused coping (indirect) or problem-focused coping (direct).
- Coping can lead to reduced stress or reappraisal
reappraisal is where an individual initially finds the encounter stressful but, after reevaluating resources available, stress subsides
Coping strategies
are a specific method, behavioural or psychological, that people use to manage or reduce the stress produced by a stressor.
Approach v avoidance coping
- Approach strategies attempt to deal directly with a stressor and avoidance strategies deal with it indirectly (i.e. protect from psychological distress).
- Avoidance strategies tend to be more maladaptive and ineffective than approach strategies
Factors in effectiveness of a coping strategy
Context-specific effectiveness (based on situational factors, personal characteristics, demands of the stressor) and coping flexibility
Context-specific effectiveness
- The strategy matches or is appropriate to the stressful situation.
For example, exercise is commonly recommended as an effective coping strategy. However, it may not be a suitable option for someone who hates all types of exercise.
Coping flexibility
- Refers to the ability to effectively modify/adjust a coping strategies according to the demands of different stressful situations. It includes the abilities to:
1. recognise whether the use of a flexible coping strategy is appropriate for a specific situation
2. select a coping strategy that suits the situational circumstances
3. recognise when the coping strategy being used is ineffective
4. discontinue an ineffective coping strategy
5. produce and implement an alternative coping strategy when required.
Limitations of the transactional model
- Lack of empirical evidence – subjective nature of responses to stressors
- We can experience a stress response without ever having thought about a situation or event (i.e. appraisal is not essential)
- Highly simplistic – primary and secondary appraisals can interact with one another and occur simultaneously
- Individuals may not always be conscious of all the factors causing them to experience a stress response
Strengths of the transactional model
- Focuses on psychological determinants of the stress response over which we have control; allows us to change our thinking
- Views stress as an interaction with the environment
- Explains why individuals respond in different ways to the same types of stressors
- Allows for the fact that stressors and the circumstances under which they occur can change over time
When can avoidance strategies be helpful?
- In the short term by reducing distress, anxiety and preventing stressors from becoming overwhelming.
- When coping with a number of stressors at the one time, selectively avoiding to deal with unchangeable aspects of a stressor by allowing for the conservation of energy to focus on other stressors that can be changed.
- Situations where nothing can be done (such as awaiting the outcome of an important medical test).
Culmulative stress
When a number of stressors occur at the same time or one after the other and the person has not had the opportunity or time to recover, the level of physiological arousal and associated bodily changes can rise and stay high.
