stress 1 Flashcards
how does our body change when we feel stress?
changes in breathing
exacerbate existing mental health conditions
changes in eating behaviour
diarrhoea / constipation
stress reactivity
the way we respond to a stressor
Stressor
a situation that causes stress to a system `
possible effects of changes in breathing due to stress?`
increased risk of asthma attack/ emphysema
hyperventilation during stress- increased risk of panic attack in those with panic disorder
problems caused by chronic stress
muscles of the body in a constant state of guardedness tension-type headache/ migraines long term heart/ blood problems -hypertension -heart attack
Everson-Rose et al. 2014
multi ethnic study of atherosclerosis
population based study on 6749 adults age 45-84 years
free of cardiovascular disease
stress measured as burden of 5 domain
chronic stress at baseline predicted increased likelihood of stroke over the follow up period
(10% increase)
Everson-Rose et al. 2014 5 domains to measure stress
health problems health problems of others job or ability to work problems relationship finances
Everson-Rose et al. 2014 10% increase held after accounting for:
race
age
sex
education
acute physical cause of stress
injury
chronic physical cause of stress
hunger
cancer
acute psychological cause of stress
deadline
acute social cause of stress
humiliation
chronic psychological cause of stress
chronic work pressure
chronic social cause of stress
chronic isolation
when does stress have negative side effects?
has short term gain at first
when it is continuous
results in chronic stress which leads to problems such as ulcers and withdrawal symptoms
what is the stress response?
fight or flight
immediate side effects of stress
arousal, increased blood supply and sugar, violent bursts of energy
1900s causes of mortality
infectious disease and childbirth
- pneumonia
- tuberculosis
- influenza
- childbirth
causes of mortality 2007
cumulative damage, chronic stressors
- heart disease
- cancer
- cerebrovascular disorders
what does the immune system protect the body from?
infection
- invading bacteria
- viruses
- foreign bodies
how does stress impact immune system?
via cortisol it can directly suppress the activity of the immune system
where are B lymphocytes produced?
bone marrow
where T lymphocytes produced
thymus gland
what did keller 1983 experiment find under normal conditions
inescapable shock lead to reduced B and T cells
what did keller (1983) find when the adrenal cortex was removed?
inescapable shock lead to no immune change (because cortisol is no longer being produced) but normal immune response to antigen (bacterial protein)
Kiecolt-Glaser et al found that bereavement tended to? what form of bereavement?
reduce immune system functioning
caring for others with alzheimer’s marital disease
Keicolt et al. 1995 study and findings
13 caregivers for relatives with dementia
13 controls
matched for household age and income
gave them a punch biopsy
wounds took longer to heal in caregivers
glaser et al 1987, exams and the immune system method
blood samples form 40 1st year medical students
1) during exam period
2) 1 month before exams
glaser et al 1987, exams and the immune system findings
during exams the immune system responses weakened
heightened risk of contracting acute infections
increased risk of epstein burr virus
parts of the brain involved in the stress response (HPA axis)
hypothalamus
anterior pituitary
adrenal cortex
hypothalamus
centrally located in the brain
generally involved in homeostasis
involved in the fight or flight response
homeostasis hypothalamus
thermoregulation
-sweating, panting, shivering
circadian rhythms
satiety and feeding
Bard (1928)
examined the effects of lesions in cats
removed most of the cerebral cortex either with or without the hypothalamus
intact hypothalamus lead to undirected rage
what hormone does the hypothalamus release?
stress hormones:
corticotropin releasing hormone (CRH)
pituitary gland
located beneath the hypothalamus
master gland
weighs 0.5 g
what does the pituitary gland produce?
somatotrophins
thyrotrophins
gondadotrophins
corticotrophins (adrenocorticotropic hormone)
what is ACTH
stress hormone released by pituitary gland
adrenocorticotropic hormone
adrenal glands
sit on top of your kidneys
release a set of hormones involved in stress
what hormones do the adrenal glands produce?
cortisol
epinephrine
cortisol
released in response to ACTH
metabolism
immune system suppression
functions of cortisol
reduces levels of inflammation 10-30 minutes after start of the stressor
help regulate blood pressure and sugar
involved in managing bodies use of carbohydrates, fats and proteins
acts on the hypothalamus to down regulate the release of ACTH and CRH
fast response to stress (hypothalamus)
stimulates the adrenal medulla to release adrenaline, which further increases the affects of the sympathetic nervous system (sympathomedullary system)
stimulates the release of noradrenaline from the locus coeruleus, acts upon brain structures and can enhance attention
fast action is via the autonomic nervous system
who coined the term fight or flight?
walter cannon
effect of adrenaline
releases stored forms of energy in muscles (proteins to glucose)
stimulates the heart and other organs
four f’s
4 f’s?
fight, fright, flight and fuck
Selye’s general adaptation syndrome
animal experiments
chronic exposure to stressors lead to a sequence of three stages
Selye’s general adaptation syndrome
alarm
resistance
exhaustion
alarm
arousal of the autonomic nervous system
primarily during first encounter with stressor
(resistance to stressor drops below normal with potential for shock)
stress hormones released into bloodstream
sympathetic nervous system activated
resistance (continued exposure to stressor)
parasympathetic system returns physiological functions to normal levels
blood glucose, epinephrine and cortisol all remain high
heart rate, blood pressure and breathing all increased
what happens to resistance to stressor overtime?
it increases, levels out at normal levels
what is resistance
adaption to environmental stressors
when does exhaustion occur?
when the stressor continues beyond the body’s capacity and has depleted the available resources
what happens in exhaustion?
stressor depletes the available resources
loss of ability to adapt to situations
susceptible to illness, even death
mobilisation of energy…
fatigue, diabetes
increased cardiovascular tone…
stress induced hypertension
suppression of digestion…
peptic ulcers
suppression of growth…
psychogenic dwarfism
suppression of reproduction
amenorrhea, impotence
suppression of immune system…
increased disease risk
sharpening of cognition….
neuron death
