Physiological and Psychological responses to stress

1. Lesson 1: Physiological & psychological
characteristics of responses to stress

2. Exposure to stressful situations and events is a common human
experience. From losing your locker key to losing your job – these events
can produce stress.
Stressor = any person, situation or
event that produces stress.
Virtually anything can be a stressor
and therefore a cause of stress to an
individual.
Stress and Health
Stress =A state of physiological and
psychological arousal produced by
internal or external stressors that are
perceived by the individual as
challenging or exceeding their ability
to cope.

3. Biopsychosocial approach to stress

4. Responses to Stress
Stress affects different people in different
ways – depending on severity, duration
and the individual.
A Stress Response = physiological (bodily)
and psychological (mental) changes
experienced when confronted by a
stressor.
Stress&can&be&classified&as&MILD,&ACUTE&or&
CHRONIC.&
Mild&stress&&?&can&be&s@mula@ng&–&low&levels&
of&arousal&can&enhance&performance.&
Acute&–&sudden&high&arousal&level.&
Chronic&–&long&term&–&can&be&damaging.&&

6. Physiological (Bodily) Responses to Stress

10. Eustress and Distress
Eustress is a positive psychological response to a stressor, as indicated by
the presence of positive psychological states such as feeling enthusiastic,
excited, active and alert. Distress, on the other hand, is a negative
psychological response to a stressor, as indicated by the presence of
negative psychological states such as anger, anxiety, nervousness, irritability
or tension.

11. Yerkes-Dodson Curve

12. The following is not examinable but
interesting and relevant to your life

13. Physiological (Bodily) Responses to Stress
• The$second$model$which$addresses$the$physiological$responses$to$stress$is$$
the$General$Adapta-on$Syndrome.!
2.#General#Adapta.on#Syndrome#
General'Adapta,on'
Syndrome'=''
A"three"stage"
physiological"stress"
response"that"occurs"
regardless"of"the"
stressor"that"is"
encountered."There"
are"three"stages"in"the"
GAS"–"Alarm"Reac;on,"
Resistance"and"
Exhaus;on.""
Research"by"Hans"
Selye.""

14. Physiological (Bodily) Responses to Stress
2.#General#Adapta.on#Syndrome#
• Cannon’s'belief'that'prolonged'stress'is'harmful'was'confirmed'by'Selye.''
• Most'of'Selye’s'stress'studies'used'rats'who'were'exposed'to'a'variety'of'
stressors.'(eg.'Tail'pulling,'electric'shocks'etc).'
• Regardless'of'the'stressor,'the'results'were'relaDvely'similar'–'enlarged'
adrenal'glands,'weight'loss,'stomach'ulcers'and'depleted'immune'system'
etc.''
• He'then'concluded'that'stress'is'nonGspecific.''
• Humans'reacted'in'much'the'same'way'to'stress.''
• Based'on'his'studies,'Selye'develop'the'three'stage'
• 'GENERAL'ADAPTATION'SYNDROME.''

15. Physiological (Bodily) Responses to Stress
2.#General#Adapta.on#Syndrome#(GAS)#
There%are%three%stages%in%the%GAS.%
Stage%One:%Alarm%Reac6on:%!
Occurs!when!the!person/animal!is!first!exposed!to!the!stressor.!!
• Body!goes!into!temporary!state!of!‘shock’!–!body!temp!and!blood!pressure!
drop.!!
• The!body!then!quickly!rebounds!from!this!during!what!is!called!
‘countershock’.!
• SympatheCc!NS!is!acCvated!and!a!reacCon!like!that!of!the!flightGflight!
response!occurs.!Arousal!is!produced!by!the!release!of!hormones!by!the!
endocrine!system:!the!pituitary!glands!secrete!ACTH,!which!causes!a!
heightened!release!of!adrenaline,!noradrenaline,!and!corCsol!by!the!adrenal!
glands!into!the!bloodstream.!!
• Organism!is!alert!and!ready.!%
The body cannot stay in this state for long without
serious consequences. Some organisms in a continuous
state of alarm have died within hours or days

16. Physiological (Bodily) Responses to Stress
2.#General#Adapta.on#Syndrome#(GAS)#
There%are%three%stages%in%the%GAS.%
Stage%Two:%Resistance:%%
• If#the#reac*on#con*nues#and#is#not#strong#enough#to#cause#death#the#
physiological#reac*on#enters#the#stage#of#resistance.##
• The#body#tries#to#adapt#to#the#stressor.#Physiological#arousal#declines#but#
remains#higher#than#normal#and#the#body#replenishes#the#hormones#
released#by#the#adrenal#glands.##
• The#organism#may#show#few#outward#signs#of#stress.#However,#the#body#
may#not#be#able#to#resist#new#stressors.##
• The#body#becomes#increasingly#vulnerable#to#health#problems.#These#health#
problems#include#ulcers,#high#blood#pressure,#asthma,#and#illnesses#that#
result#from#impaired#immune#func*on.#

17. Physiological (Bodily) Responses to Stress
2.#General#Adapta.on#Syndrome#(GAS)#
There%are%three%stages%in%the%GAS.%
Stage%Three:%Exhaus4on:%%
• Severe%long*term%or%repeated%stress%will%cause%the%organism%to%enter%the%
third%stage,%the%stage%of%exhaus9on.%%
• The%immune%system%and%the%body's%energy%reserves%are%weakened%un9l%
resistance%is%very%limited.%%
• If%the%stress%con9nues,%disease%and%physiological%damage%become%
increasingly%likely%and%death%may%result.%

18. Physiological (Bodily) Responses to Stress
2.#General#Adapta.on#Syndrome#(GAS)#