stress Flashcards
what is stress
a state of pysiological strain caused by a stressor that disturb the function of the body
- mismatch between the demands made upon an individual and their ability to meet these demands
what are the symptoms of stress
fight or flight: increased hr, increased blood pressure, sweaty palms, rapid breathing, inhibited digestion, dry mouth
the PAS pathway
- endocrine system
- hormones travel via bloodstream
- slower
- HYPOTHALAMUS activates the PITUITARY GLAND which causes ACTH to be released which acts on the ADRENAL CORTEX which releases CORTISOL
- stimulates liver, increasing glucose release and supresses the immune system
- rest and digest
the SAM pathway
- nervous system
- impulse
- electrical signal
- quickly
- the HYPOTHALAMUS activates the SYMPATHETIC BRANCH of the ANS which causes the ADRENAL MEDULLA to release ADRENALINE and NORADRENALINE
- increases heart rate, blood pressure, inhibits digestion
- fight or flight
cortisol
- hypothalamus and pituitary gland sense if blood contains correct levels of cortisol
- if it is too low, the brain adjusts amount of hormones it makes
- adrenal gland picks up on these signals
- then release the correct level of cortisol
what are cortisol receptors
- in most cells in your body
- receive and use the hormone in different ways
- when body is on high alert cortisol can alter and shut down functions that get in the way
- these could include, digestive system, reproductive, immune systems
what is the role of cortisol
- constricts blood vessels and increases blood pressure to enhance the delivery of oxygenated blood
- advantageous for fight or flight situations
- however over time constriction can lead to vessel damage and plaque build up= blockage- cardiovascular disorders
- cortisol plays important role in regulating your bodys stress response, helping control your bodys use of fats, proteins or carbs or metabolism
- cortisol helps to maintain blood pressure, immune function, and the bodys anti inflammatory process
what is cushings syndrome
too much cortisol
what is addisons disease
no/little cortisol
newcomer et al (1999)
- found participants given levels of cortisol high enough to produce blood sugar levels similar to those experiencing major stress events were poorer at recalling in the memory task
- moderate levels of cortisol may have assisted memory
results - high levels of cortisol interfered with the recall
- moderate levels of cortisol assisted the recall or passage
- makes sense as there are cortisol receptor sites on the hippocampus which is responsible for the transfer of info stm to ltm
what is the general adaption syndrom (GAS)
the bodys organised responses to stress as educated by hans seyle.
- it progresses through 3 stages; the alarm, the stage of resistance, and the stage of exhaustion
what is hans seyle’s research
- all research carried out on lab rats
- after exposing rat to most extreme condition, then injected them with substances that were harmless
- rats became ill even with the harmless injection: stumach ulcers, shrunk thymus
- it didnt matter what was in the injection, it was a response to stress
- rats getting stressed as a result of continuous procedures they were undergoing
- humans react the same way
what is the alarm reaction stage
- occurs shortly after stressful event
- trigger hypothalamus to produce CRF
- stimulates pituitary glands production of ACTH
- acts on adrenal cortex which produce corticosteroids
- hypothalamus also activates the sympathetic branch of the ANS to stimulate production of adrenaline and noradrenaline
- body prepared for fight or flight
what is the resistance stage
- Bodys ANS resists the impact of stressful stimulus
- body’s resources are fully mobilised to cope with the stressor
whst is the exhaustion stage
- body fails to cope with the distressing stimulus
- physiological consequences include effects on the adrenal glands which are enlarged but depleted and an endocrine system generally thrown into disarray
- selye argued that all body tissues and processes can be affected and in extreme cases become diseased
evaluation of GAS
- ignored individual differences e.g. gender, personality and differences in psychological reactivity = universal responses to stress however individual differences modify the effects of stress.
- supported by lots of scientific research however different stressors produce different patterns of physiological activity and so the GAS is not a single passive response.
what is immunosuppression
suppression of the immune system due to the action of the cortisol as they suppress leukocyte activity and stops production of white blood cells
what can long term stress cause
shrinkage and damage to thymus gland= permanently reduces number of white blood cells available to fight invading antigens
mechanisms of immunosuppression
sustained production of cortisol- reduces immune function
interferes with activity of white blood cells- reduced ability to fight infections
stress linked to cardiovascular disorders
what do lymphocytes do
- recognise and destroy harmful viruses and bacteria that invade the body
- lock onto invaders, multiply rapidly and destroy them
- b cells = produce antibodies released into fluid
- t cells= if invader gets into cell these cells lock on multiply and destroy
what is cellular immunity
- number of different types of lymphocytes t cells: natural killer! memory and helper t cells
- work together to attack intracellular (within cells) pathogens such as viruses
- form in thymus gland
what is humoral immunity
- uses b cells
- work together to attack extracellular ( outside cells) pathogens such as bacteria and parasites
- form in bone marrow
kiecolt- glaser et al’s (1984) study on stress and the immune system
- natural experiment
- 75 medical students
- blood samples taken : (a) one month before their final exams (low stress) and (b) during the exams (high stress)
- immune functioning was assessed by measuring NK cell activity (t cells) in blood samples
- students given questionnaires to assess psychological variables such as life events loneliness
results - NK cell activity was significantly reduced in second sample compared to the first sample
- NK cell activity was most reduced in participants who reported high levels of life events and loneliness
effects of stress on cardiovascular systems
- blood pressure increases as part of f or f response of ANS
- raised bp increases hr
- damaged blood vessels because bloood is being pumped faster and so at a higher pressure through the blood vessels
- arteries become scarred, hardened, less elastic
- may be unable to supply the amount of blood the body’s organs need
what can acute and chronic stress lead to
- high bp
- chd
- stroke
- these can also be linked to other lifestyle factors
- stress can lead to increased glucose levels which can clump the blood vessels- blood clot
what is arteriosclerosis
hardening of arteries with increased sugar production and the fact that the stress response stops digestion speed up the clogging of arteries
if one vessel becomes completely closed off, the heart muscle is damaged = heart attack
williams et al
- see if anger was linked to heart disease
- questionnaire to 13,000 people
- none had heart disease
- contained 10 q anger scale
- after 6 years, health status of participants checked
- 256 developed heart attacks
- those scored highly on anger scale 2 and a half times more likely to have a heart attack than those with low
- people who scored moderately were 35% more likely to experience some form of heart problems
life events and stress
- throughout lives we all experience major life changing events e.g. death of relative, married, moving house etc
- they r events that might cause stress and illness: can be positive/negative - require adjustment