Copyright © Allyn & Bacon 2007 How and Why Do We Experience Stress? The human stress response to perceived threat activates thoughts, feelings, behaviors,

Copyright © Allyn & Bacon 2007

How and Why Do WeHow and Why Do WeExperience Stress?Experience Stress?

The human stress response to perceived threat activates

thoughts, feelings, behaviors, and physiological arousal that normally promote adaptation

and survival

Stress and Stressors

• Stress • A physical and mental response to

a challenging or threatening

situation

Stressor A stressful stimulus

…. a condition demanding adaptation

Primitive Stressors1. Starvation 2. Exposure to the

elements 3. Mortal attack4. • Humans who respond

more quickly to danger survived

A Model of Stress


Traumatic Stressors

• A situation that threatens one’s physical safety, arousing feelings of fear, horror, or helplessness


Catastrophe


• Identified five stages that occur in the wake of natural disasters

1. Psychic numbness: Shock, confusion2. Automatic action: Little awareness/recall of the

experience3. Communal effort: People pool resources and

collaborate4. Letdown: Depletion of energy, feel abandoned5. Recovery: Survivors adapt to changes created by

the catastrophe

Cohen and Ahearn


Post-Traumatic Stress Disorder• Delayed stress reaction in which an

individual involuntarily re-experiences emotional, cognitive, and behavioral aspects of past trauma


The Physical Stress Response• The physical response to nearly any stressor

follows the same sequence.1. Initial arousal2. Protective behavioral reaction, often fight-or-

flight3. Internal responses to the autonomic nervous

system and endocrine system4. Decrease in the effectiveness of the immune

system


The Physical Stress Response

• Arousal: Increased physiological state


The Physical Stress Response• Acute Stress

A temporary pattern of arousal caused by a stressor with a clear onset and limited duration

• Example: flashing blue lights in your rearview mirror


The Physical Stress Response

• Chronic Stress A continuous state of stressful arousal persisting over time

• Example: A bad marriage


The Physical Stress Response• Fight-or-Flight Response A

sequence of internal processes that prepares the organism for struggle or escape


The Physical Stress Response• Withdrawal:

If fight or flight is not possible, or stressor is too much to handle, the organism may ‘freeze’

• Ex: Deer in the headlights


The Physical Stress Response• Passive Fear Response: • An individual responds to a threat

by becoming emotionally withdrawn and disengaged.

• Example: A rabbit, instead of running, eludes a predator by hiding or remaining still


The Physical Stress Response• Tend-and-Befriend Model • A stress response model

proposing that females are biologically predisposed to respond to stress by nurturing and protecting offspring (tend)

• and seeking out a social group for joint protection (befriend)

•

Tending to offspring in times of stress is vital to ensuring the survival of the species.

Tending activities also reduce biological stress responses in both parents and offspring,

Befriending leads to substantial mental and physical health benefits in times of stress.Does not replace the

“Fight or Flight” response


The General Adaptation Syndrome (GAS)

• A pattern of responses to any serious chronic stressor

• Prolonged stressor response can contribute to heart disease, ulcers, arthritic, asthma,

even death


General Adaptation SyndromeGeneral Adaptation Syndrome

G. A. S.3 Stages1. Alarm

2. Resistance3. Exhaustion

Healthy Adaptation or Illness


Stage One - Alarm Reaction

• 1. Body mobilizes its resources to cope with a stressor

• 2. Hypothalamus sets off a response through the endocrine system

• 3. Adrenal hormones are released• 4. The sympathetic nervous system is

activated

IF STRESSOR IS NOT REMOVED IN TIME, THE ORGANISM MOVES TO NEXT STAGE

Sympathetic --Mobilize energy from stores, inhibit further storage

Inhibit digestion, growth, reproduction, immunity

--Increase HR, BP, breathing--Fight or flight response--Analgesia--Aspects of senses and memory improve


Stag Two - Stage of Resistance

• Arousal (Alarm reaction) subsides• The parasympathetic system activates adrenal

output slows

• If a second stressor is introduced, the organism may not be able to adapt

IF STRESSOR IS NOT REMOVED IN TIME, THE ORGANISM MOVES TO NEXT STAGE

ResistanceBody tries to adapt to stressorHormonal changes to cope with stressConservation of resourcesEffects on activity level, feeding etc..


Stage Three - Stage of Exhaustion• Organism tires fighting stressor• Symptoms of Alarm Stage (Stage One)

reappear• Parasympathetic system overcompensates in

an attempt to stop surging hormones

IF STRESSOR DOES NOT DISAPPEAR IN TIMEDEATH OCCURS


Resistance

Resistance– the body

seems to adapt to the presence of the stressor

Alarm Reaction

Alarm reaction – the body

mobilizes it’s resources to cope with a

stressor

The General Adaptation Syndrome

Exhaustion

Illness/death

Exhaustion– the body

depletes it’s resources

Level ofnormal resistance

Successful Resistance


Stress and the Immune System

• The human immune system response, which evolved to respond to short-term stressors, may react to chronic stressors by breaking down and turning on itself


Stress and the Immune System• Psychoneuroimmunology

Multidisciplinary field that studies the influence of mental states on the immune system

• Cytokines (site-toe-kines)

• Hormone-like chemicals facilitating communication between brain and immune system

cytokinesAfter they alert the brain to distress, the brain releases its own cytokines to reduce energy output, causing symptoms like fever or listlessness, responses that usually help fight disease

Also may cause depression, prolonging stress and illness


Personality Types and Stress

• Type A –• behavior pattern characterized by intense,

angry, competitive, or perfectionist responses to challenging situations

• Type B –• behavior pattern characterized

by a relaxed, unstressedapproach to life


Type A– Highly driven– Competitive– Impatient– Aggressive– Feel rushed and

under pressure– Find it difficult to

give up control or power


Type B– Relaxed– More

focused on the quality of life

– Less ambitious and less impatient.


Psychological Responses to Stress

• Learned HelplessnessLearned Helplessness Passive resignation following reoccurring Passive resignation following reoccurring failure or punishmentfailure or punishment


Resilience • Capacity to adapt, achieve well-being, and

cope with stress, in spite of serious threats to development


End of Chapter 8

Documents

Copyright © Allyn & Bacon 2007 How and Why Do We Experience Stress? The human stress response to perceived threat activates thoughts, feelings, behaviors,