3.6C Occupational Health & Safety - Literature Summary
Problem 1
1.1 What is Stress
Misconceptions about stress
1. You should strive to eliminate all stress in your life
Stress can have positive implications Eustress
2. Stress is just “in your head”. It cannot really harm you
3. Stress is really just anxiety or nervous tension. If you could calm
down, then you would not be stressed
This is an oversimplification
People can exhibit physiological stress reactions (increased HR and BP)
even when asleep
4. Stress only implies excess, such as too much work or stimulation
Definitions of Stress
Stimulus Definitions
Stressor An event/situation in the environment that contributes to or
causes a noxious or disruptive experience Focuses on the external
forces or demands applied to an object
Implication of the definition Stress can be defined using objective or
external criteria Suggest direct target of change
Flaws of this definition:
o No two people respond to a stressor identically
o This perspective generally assumes that no stress at all is best
Untrue
Response Definitions
Focus on the reaction the organism has to the stressor
The response can take many forms Immediate, reflective, physiological
Strain Long-term or chronic changes in response to a stressor
The response to the stressor is always internal (physiological changes in the
body) BUT it may or many not have over manifestations
Although the definition acknowledges the influence of other factors
Emphasis is always on the stress response
Associated with medical or biological perspectives of stress
Flaws of this definitions:
, 3.6C Occupational Health & Safety - Literature Summary
o Different responses can be associated with different stressors, and they
may change over time
o The boy may undergo a response very similar to a stress response when
no stimulus is present
o Inadequate because the stressor cannot be ignored
o Knowledge about the stressor is important if any type of intervention is
desired
Stimulus-Response (Interactive) Definitions
Conceive stress as a result of an interaction between environmental stimuli
(stressors) and individual responses (usually in the form of strains)
More complex than the previous definitions Stressor-response
interaction can take many forms depending on both the nature of the stressor
and the response
Relational definition Deals with the relationship between the person and
the environment (stimulus) that is appraised by the person as taxing or
exceeding their resources and endangering his or her well-being (response)
This definition can also accommodate the influence of factors
Perceptions/appraisals
Stress (based on this definitions) Any circumstance (stressor) that places
special physical and/or psychological demands on an organism leading to
physiological, psychological, and behavioural outcomes
o If these demands persist over time Long-term or chronic
undesirable outcomes or strains may result
For most stressors The stress response must be preceded by the
perception that the stressor is indeed threatening or stressful
o A psychological appraisal occurs that determines the severity of the
stressor
o This appraisal may then lead to specific short-term outcomes and
(eventually) chronic outcomes or strains
o The appraisal and outcomes may be affected by characteristics of
the person group, and/or situation:
Person High conscientiousness Group Low group
morale
Situation Inadequate equipment or machinery
o These characteristics are often referred to as stress modifiers or
moderators
Stress A function of the stressor(s), psychological appraisal, short-term
stress outcome(s), strains, and stress moderators
o Stimuli become stressors only when perceived as such
At that point, any type and number of modifiers can influence
the link between the stressor and its outcome
o Once perceived as stressful The stimulus triggers a series of short-
term physiological, psychological, and behavioural outcomes
If the stressor remains over time The short-term
outcomes can become more serious
Stressors may be either chronic or acute:
o Chronic When the stressor persists over time
, 3.6C Occupational Health & Safety - Literature Summary
Depends on whether the stressor is removed entirely or at
least attenuated
o Acute When a stressor is first appraised as stressful
The Psychology of Stress: The Role of Appraisal
Responses to an environmental stressor (heat) depend on different
factors:
o The overall number and strength of the stressor encountered
o The person’s ability to cope with them
The psychological interpretation of these stimuli is critical for predicting if
and how much stress is perceived
Cognitive appraisal Evaluative process of the stressor
o Psychological stressors must be appraised as stressful before they
are truly stressors Stress is in the eye of the beholder
o Appraisal occurs at two different points:
Primary appraisal When the situation is perceived as
being stressful
Is the situation stressful?
Secondary appraisal When some type of response is
consciously chosen
What can I do about it?
o Reappraisal Can occur based on feedback from
primary/secondary appraisals
, 3.6C Occupational Health & Safety - Literature Summary
The Physiology of Stress
The body undergoes a well-established sequence of physiological
reactions
Physiological reactions are assumed to be qualitatively similar (but not
identical) regardless of the stimuli that provoked them
The Fight or Flight Response (F/F)
When faced with a threat (stressor) The organism’s body prepares for
combat or run to safety Changes in nerves and glands in the body
happens
When the organism perceives a stressor A message is sent to the
hypothalamus
The hypothalamus immediately activates the autonomic nervous system
(ANS)
o Specifically the sympathetic branch Prepares the body into an
aroused state
o The sympathetic nerve fibers release noradrenaline
(norepinephrine) Regulates body functions
o Through the release of noradrenaline Increased heart rate, brain
alertness, BP Constriction of blood vessels
Almost simultaneously with the sympathetic activity The hypothalamus
activates the medulla of the adrenal glands
o The medulla releases catecholamines Noradrenaline and
adrenaline (80%)
Bodily changes of this process Commonly associated with stress
o Hair erection (goosebumps)
o Dilated pupils
o Decreased digestive activity and vasoconstriction of blood vessels
Limit the biological activities that are not absolutely necessary to
deal with the stressor
Problem 1
1.1 What is Stress
Misconceptions about stress
1. You should strive to eliminate all stress in your life
Stress can have positive implications Eustress
2. Stress is just “in your head”. It cannot really harm you
3. Stress is really just anxiety or nervous tension. If you could calm
down, then you would not be stressed
This is an oversimplification
People can exhibit physiological stress reactions (increased HR and BP)
even when asleep
4. Stress only implies excess, such as too much work or stimulation
Definitions of Stress
Stimulus Definitions
Stressor An event/situation in the environment that contributes to or
causes a noxious or disruptive experience Focuses on the external
forces or demands applied to an object
Implication of the definition Stress can be defined using objective or
external criteria Suggest direct target of change
Flaws of this definition:
o No two people respond to a stressor identically
o This perspective generally assumes that no stress at all is best
Untrue
Response Definitions
Focus on the reaction the organism has to the stressor
The response can take many forms Immediate, reflective, physiological
Strain Long-term or chronic changes in response to a stressor
The response to the stressor is always internal (physiological changes in the
body) BUT it may or many not have over manifestations
Although the definition acknowledges the influence of other factors
Emphasis is always on the stress response
Associated with medical or biological perspectives of stress
Flaws of this definitions:
, 3.6C Occupational Health & Safety - Literature Summary
o Different responses can be associated with different stressors, and they
may change over time
o The boy may undergo a response very similar to a stress response when
no stimulus is present
o Inadequate because the stressor cannot be ignored
o Knowledge about the stressor is important if any type of intervention is
desired
Stimulus-Response (Interactive) Definitions
Conceive stress as a result of an interaction between environmental stimuli
(stressors) and individual responses (usually in the form of strains)
More complex than the previous definitions Stressor-response
interaction can take many forms depending on both the nature of the stressor
and the response
Relational definition Deals with the relationship between the person and
the environment (stimulus) that is appraised by the person as taxing or
exceeding their resources and endangering his or her well-being (response)
This definition can also accommodate the influence of factors
Perceptions/appraisals
Stress (based on this definitions) Any circumstance (stressor) that places
special physical and/or psychological demands on an organism leading to
physiological, psychological, and behavioural outcomes
o If these demands persist over time Long-term or chronic
undesirable outcomes or strains may result
For most stressors The stress response must be preceded by the
perception that the stressor is indeed threatening or stressful
o A psychological appraisal occurs that determines the severity of the
stressor
o This appraisal may then lead to specific short-term outcomes and
(eventually) chronic outcomes or strains
o The appraisal and outcomes may be affected by characteristics of
the person group, and/or situation:
Person High conscientiousness Group Low group
morale
Situation Inadequate equipment or machinery
o These characteristics are often referred to as stress modifiers or
moderators
Stress A function of the stressor(s), psychological appraisal, short-term
stress outcome(s), strains, and stress moderators
o Stimuli become stressors only when perceived as such
At that point, any type and number of modifiers can influence
the link between the stressor and its outcome
o Once perceived as stressful The stimulus triggers a series of short-
term physiological, psychological, and behavioural outcomes
If the stressor remains over time The short-term
outcomes can become more serious
Stressors may be either chronic or acute:
o Chronic When the stressor persists over time
, 3.6C Occupational Health & Safety - Literature Summary
Depends on whether the stressor is removed entirely or at
least attenuated
o Acute When a stressor is first appraised as stressful
The Psychology of Stress: The Role of Appraisal
Responses to an environmental stressor (heat) depend on different
factors:
o The overall number and strength of the stressor encountered
o The person’s ability to cope with them
The psychological interpretation of these stimuli is critical for predicting if
and how much stress is perceived
Cognitive appraisal Evaluative process of the stressor
o Psychological stressors must be appraised as stressful before they
are truly stressors Stress is in the eye of the beholder
o Appraisal occurs at two different points:
Primary appraisal When the situation is perceived as
being stressful
Is the situation stressful?
Secondary appraisal When some type of response is
consciously chosen
What can I do about it?
o Reappraisal Can occur based on feedback from
primary/secondary appraisals
, 3.6C Occupational Health & Safety - Literature Summary
The Physiology of Stress
The body undergoes a well-established sequence of physiological
reactions
Physiological reactions are assumed to be qualitatively similar (but not
identical) regardless of the stimuli that provoked them
The Fight or Flight Response (F/F)
When faced with a threat (stressor) The organism’s body prepares for
combat or run to safety Changes in nerves and glands in the body
happens
When the organism perceives a stressor A message is sent to the
hypothalamus
The hypothalamus immediately activates the autonomic nervous system
(ANS)
o Specifically the sympathetic branch Prepares the body into an
aroused state
o The sympathetic nerve fibers release noradrenaline
(norepinephrine) Regulates body functions
o Through the release of noradrenaline Increased heart rate, brain
alertness, BP Constriction of blood vessels
Almost simultaneously with the sympathetic activity The hypothalamus
activates the medulla of the adrenal glands
o The medulla releases catecholamines Noradrenaline and
adrenaline (80%)
Bodily changes of this process Commonly associated with stress
o Hair erection (goosebumps)
o Dilated pupils
o Decreased digestive activity and vasoconstriction of blood vessels
Limit the biological activities that are not absolutely necessary to
deal with the stressor
