Physiology and Psychology of stress Flashcards
(38 cards)
define stress
Stress is defined as the body’s nonspecific response or reaction to demands made on
it, or to disturbing events in
the environment
when does stress arise
Stress arises when individuals perceive that they cannot adequately cope with the demands being made on them, or with threats to their well-being
what are the theories of stress
- Fight-or-flight theory (Cannon,
1932) - General Adaptation Syndrome
(Selye, 1956) - Cognitive Appraisal Theory
(Lazarus & Folkman, 1984) - Generalised Unsafety Theory
of Stress (Brosschot et al.,
2018)
Fight-or-flight theory (Cannon,
1932)
- When an organism perceives threat, the
body is rapidly motivated and aroused via
Sympathetic nervous system
Endocrine system - organism’s physiological response allows
organism to attack threat (aggressive,
active response -fight) or flee (withdrawal from the threat) - Adaptive role, as allows for rapid
response to threat (i.e., SAM and acute
stress), but this can also be harmful (i.e.,
chronic activation of HPA axis where
dysregulation can cause both physical
and psychological harm)
General Adaptation Syndrome
(Selye, 1956)
- Non-specific response: the body responds to stress with the same pattern of physiological responding, regardless of the type of stressor
- Organism confronts stress, mobilises for action (fight or flight -SNS is stimulated), occurs with continued exposure to the stressor then PNS compensates, and lastly physiological resources are then depleted at exhaustion phase
Criticisms of Canon and Selye’s models - name 3
Cognitive appraisal is important and it’s not addressed
stress responses is influenced by perceptions, individual differences, pre-existing physical and mental health
Not all stressors produce same physiological response
Damage/exhaustion may result from continued activation (‘resistance’) as opposed
to depletion of physiological resources
Stress is assessed as an outcome
Cognitive Appraisal Theory
(Lazarus & Folkman, 1984)
Stress results from imbalance between demands & resources
Psychological stress occurs when an individual perceives environmental
demands as exceeding their adaptive capacity
The interpretation of the stressful event is more important than the event itself
Takes anticipatory anxiety into account
Appraisal involves a two-step process:
Primary appraisal process –
assessment of situation
Secondary appraisal process –
assessment of coping abilities
& resources
Interpretation of a stimulus, presented in a given situation, results in
production of stress response IF the stimulus is considered to be a threat
Generalised Unsafety Theory of Stress
Emphasising importance of perceived safety as opposed to perceived danger
Stress response is always active, or on standby, perception of safety in environment regulates and inhibits the stress response
define stress, with regards to the physiology of stress
Stress = exposure to noxious stimuli (stressors)
(E.g. physical trauma, prolonged heavy exercise, infection, shock, prolonged exposure to cold, sleep deprivation, pain, fright, emotional stress)
regarding the physiology of stress, what does it result in
Results in disruption of homeostasis (body responds to demands) and a cascade of changes in CNS, endocrine and immune systems
Sympathetic nervous system effects of adrenaline and noradrenaline - name 3
- Increased hepatic and muscle glycogenolysis (provides quick source
of glucose) - Increased breakdown of adipose tissue triacylglycerol (provides a supply of glycerol for gluconeogenesis and of fatty acids for
oxidation) - Decreased fatigue of skeletal muscle
- Increased cardiac output secondary to increased cardiac contractility and heart rate
- Diverting blood from viscera to skeletal muscle by means of vasoconstriction in the visceral organs and vasodilation in the skeletal muscles
- Increased ventilation + dilated bronchi
- Increased coagulability of blood
- Dilated pupils
effects of cortisol
Effects on organic metabolism
* Stimulation of protein catabolism
* Stimulation of liver uptake of amino acids and their conversion to glucose (gluconeogenesis)
* Inhibition of glucose uptake and oxidation by many body cells (“insulin antagonism”) but not by brain
* Stimulation of triacylglycerol catabolism in adipose tissue, with release of glycerol and fatty acids into the blood
2. Enhanced vascular reactivity - increased
ability to maintain vasoconstriction in response to noradrenaline and other stimuli
3. Unidentified protective effects against the
damaging influences of stress
4. Inhibition of inflammation and specific immune responses (Anti-inflammatory response)
other hormones, apart from adrenaline and cortisol, released during stress
- Aldosterone
- Vasopressin (ADH)
- Growth hormone
- Glucagon
- Β-endorphin
respiratory effects of acute stress
Rapid shallow breathing
Cardiovascular effects of acute stress
- ↑ HR,
- Stronger contractions
- Dilation heart
- Redirection blood to large
muscle group
respiratory effects of chronic stress
dysregulation of ANS
Bronchial hyperresponsiveness and
inflammation
Exacerbation asthma, COPD
cardiovascular effects of chronic stress
Oxidative stress, endothelial
dysfunction, inflammation
Atherosclerosis
Compromised vascular function,
hypertension
dyslipidemia
GI effects of stress
GI EFFECTS
(activating α-adrenergic rec in SM)
* Delayed gastric emptying
* ↓ intestinal transit
* ↓ blood flow to gut
* Inhibit GI secretion and nutrient
absorption
musculoskeletal effects of stress
MUSCULOSKETAL (Chronic effects prologned
cortisol
* Muscle wasting
* ↓ bone density (inhibit osteoblast activity and
promote osteoclast function)
* Tension headaches, TMJ disorder, prolonged
recovery injury
immune system effects of chronic stress
- Suppress immune function
(inhibit production of pro
inflammatory cytokines) - Reduce activity of immune cells
- Infection susceptibility
- Delayed wound healing
- Exacerbate inflammatory
conditions
REPRODUCTIVE system effects of chronic stress
- Suppress Gonadotropin
releasing hormone from
hypothalamus, ↓ LH, ↓ FSH - Menstrual irregularities
- Anovulation / infertility
- Erectile dysfunction, ↓ sperm
quality - Exacerbate PCOS
trauma response of flight
Chronic rushing / always on go
Feeling uncomfortable / panic when still
Difficulty maintaining relationships
Feels trapped easily
Struggle with rest time, overworks
Often presents as anxiety / panic attack
trauma response of fight
- Explosive, unpredictable temper
- Taunt, mock, insult, shame
- Yell, scream
- Protect self at any cost
trauma response of flop
- Total bodily collapse
- Loss of control of bodily
functions - Total disorientation
- Appears disengaged and lacking
emotions - Complete submission (to the stressor)
