Physiological Psychology

STRESS

Section 1

Stress as a bodily response

Section 2

Sources of stress

Section 3

Critical Issues: Stress management

What is stress?

Pressures, demands (stressors),exert force on the body, stress isthe body’s response to this.

A stress response is an innate,defensive and adaptive reaction

Stress levels also depend onwhether the person feels that theycan cope with demands placed onthem or not

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Major Types of Stress

• Frustration: blocked goal• Conflict: incompatible

motivations– Approach-approach– Approach-avoidance– Avoidance-avoidance

• Change: having to adapt– Social Readjustment

Rating Scale– Life Change Units

• Pressure– Perform/conform

Stress Definition

Stress is a state of psychological and physical tension produced when an individual perceives that they are unable to cope with the demands imposed on them by a stressor.

The consequent state of tension can be adaptive (eustress) or maladaptive (distress)

Effects of stress

STRESSORS

Family Relations

Disagreements

Money Worries

Need to Succeed

Exams

Friends

Decisions

New Situations

FLIGHT

FIGHT

RETURN TO NORMAL

COPING

COPING STRATEGIES

RELAXATION

NOT COPING

POSSIBLE DISEASE OR MENTAL ILLNESS

EXHAUSTION

POOR DIET

NO EXERCISE

NEGATIVE THOUGHT

IRRITABILITY

Responding to Stress Emotionally

• Emotional Responses– Annoyance, anger, rage– Apprehension, anxiety,

fear– Dejection, sadness, grief– Positive emotions

• Emotional response and performance– The inverted-U-

hypothesis

Responding to Stress Physiologically

• Physiological Responses– Fight-or-flight response– Selye’s General Adaptation Syndrome

• Alarm • Resistance• Exhaustion

The Biology Of StressPHYSIOLOGICAL AROUSAL :

Walter Cannon(1932) The response to stress

Stress and the nervous system

Neurons

Neurotransmitters

AUTONOMIC NERVOUS SYSTEM

Automatically responds to stressor

Sympathetic Parasympathetic

Sympathetic Response to Stress

Hypothalamus causes:Increases arousal in the sympathetic nervous

system• Increased heart rate & blood pressure• Constriction of peripheral blood vessels• Respiration rates increase• Bronchial tubes dilate • Pupils dilate • Digestive processes decreaseSympathetic activation prepares the body for

intense motor activity

Parasympathetic response to stress

Serves regenerative, growth-promoting, energy-conserving functions

Its effects include the opposite of the effect of the sympathetic nervous system

Functions under normal, non-stressful conditionsAlso activated by the hypothalamus• re-establishes homeostasis in the system• reconstructive process following stressful experience• slows the heart rate & decreases blood pressure• decreases muscle tension• slows respiration• neutralizes fight or flight response

ENDOCRINE SYSTEM

GLANDS

HORMONES

Contrasting Communication Systems

Nervous Endocrine

Consists of nerve cells

Acts by transmitting nerve impulses

Acts rapidly

Direct control

Specified localised effects of neurotransmitters

Short lived effects

Consists of ductless glands

Acts by releasing hormones

Acts slowly

Indirect control

Hormones spread around body

Hormones remain in blood for some time

Structure of the Endocrine System• The endocrine system consists of ductless

glands distributed throughout the body• The neuroendocrine system is made of those

endocrine glands that are controlled by the nervous system

• Glands of the endocrine and neuroendocrine systems secrete chemicals called hormones

• Hormones move into the blood stream to be carried throughout the body

• Specialized receptors on target tissues or organs allow hormones to have specific effects even though they circulate throughout the body

Endocrine Responses to StressHypothalamus causes:• The pituitary gland to secrete adrenocorticotropic

hormone (ACTH) that stimulates the adrenal cortex• Sympathetic fibers to directly activate the adrenal

medulla• The adrenal glands are located on top of each

kidney• Each gland is composed of:

– an outer covering: the adrenal cortex– an inner part: the adrenal medulla

• Both secrete hormones that are important in the stress response

Homeostasis

The process of maintaining a reasonable constant internal environment in the body.

98.6 F or

37 ºC

Work together to control stress response

SAM

Sympathetic Adrenal Medullary System

HPA

-Hypothalamic

-Pituitary

-Adrenal - axis

Effects of SAM activity

• Heightened activity of SAM prepares us for Fight or Flight.

Increase in energyIncreased alertnessIncreased blood flow to the musclesIncreased heart and respiration rateReduced activity in digestive systemIncreased release of clotting factors in the bloodAdrenaline and Noradrenaline increase the output

of the heart ,which can cause increase in Blood Pressure.

Adrenomedullary Response - SAM

Occurs through the activation of the sympathetic-adrenal medulla (SAM) complex:

• Perception of stress causes the hypothalamus (via nervous connection) to activate sympathetic fibers

• Sympathetic fibers activate the adrenal medulla• Adrenal medulla secretes the catecholamines:

epinephrine & norepinephrine This causes:• Increased heart rate, blood pressure, breathing

rate & blood glucose levels• Shuts down digestive system• Rapid, short-lived response to stress

Adrenocortical Response - HPA

Occurs through the activation of the hypothalamus-pituitary-adrenal (HPA) cortex complex:

• Perception of stress causes the hypothalamus to release ACTH releasing hormone

• This causes the anterior pituitary to secrete ACTH

• ACTH stimulates the adrenal cortex to secrete glucocorticoids and mineralocorticoids

Glucocorticoids• Protein and fat get metabolized into glucose• Reduce inflammation, suppress immune cellsMineralocorticoids • Blood volume and pressure increase

Sympathetic and Endocrine Responses to Stress

• Stress perception causes a chain reaction:SAM• rapid, short-term stress reaction• the sympathetic NS stimulates the adrenal

medulla• the adrenal medulla produces epinephrine and

norepinephrineHPA• slower but longer-lasting response• the pituitary releases ACTH• ACTH causes the adrenal cortex to release

glucocorticoids and mineralocorticoids

Effects of HPA activity

+ Cortisol is important for coping with long term stress,it maintains a steady supply of fuel.

+Glucocorticoids conserve glucos for neural tissues, elevate or stabilise blood glucose levels,mobilise protein reserves, conserve salts and water.

+Cortisol helps reverse bodies initial stress responses and helps body to revert to a stable state.

Effects of HPA activity

- The blood has elevated levels of glucose (for energy) and hormones (ACTH and adrenaline) so the body continues to use its resources fast.

- The anti inflammatory action of glucocorticoids slows wound healing

- Glucocorticoids suppress the immune system which protects the body against viruses and bacteria.(so we are more likely to pick up infection.)

General Adaptation Syndrome

G . A . S

Hans Selye(1936) - ‘STRESS’ research PIONEER

Rats showed same symptoms in response to all of

Stimuli.

General state of ‘stress’

The General Adaptation Syndrome (1)

Defined by Selye in 1956. Comprises 3 stages:Stage I: Alarm• The body’s defences against stressors are

mobilized through activation of the sympathetic nervous system

• Activation of the SAM complex• Arousal of the sympathetic nervous system

releases hormones (adrenaline) that help prepare the body to meet stress and danger

• Highly adaptive short term response to an emergency situation

The General Adaptation Syndrome (2)

Stage II: Resistance• The body enters this stage if the stress is

prolonged• Activation of the HPA complex• Arousal is lower• But the body continues to draw on internal

resources at an above normal rate• Outwards appearance seems normal• Physiologically, the body’s internal functioning is

not normal• Sets the stage for diseases of adaptation (e.g.,

peptic ulcers, ulcerative colitis)

The General Adaptation Syndrome (3)

Stage III: Exhaustion• Continued exposure to the same stressor

drains the body further• The capacity to resist is depleted• Illness results• This stage is characterized by activation

of the parasympathetic division of the ANS

• But at an abnormally low level • In severe cases, results in death

STAGE 1 . ALARM:

STAGE 2. RESISTANCE

STAGE 3. EXHAUSTION

Evaluation of GAS

+ Pioneering research into stress+ Alerted medicine to the importance of stress in disease- Not much attention paid to SAM , the relationship

between SAM and HPA not fully appreciated- Stress does not always produce the same physiological

patterns. Mason (1975)different patterns of adrenaline/noradrenaline and cortisol for different stressors.

- Criticised for use of non human animals- Suggestion that people respond in a passive way to

stress. Mason.

How does stress cause physical illness?

DIRECTLY INDIRECTLY

SUPPRESSING THE IMMUNE SYSTEM

Leucocytes (white blood cells)

Lymphocytes (B Cells or T Cells)

Anti bodies

Natural killer cells

Endorphins

CARDIOVASCULAR DISORDERS

Hypertension

CHD

Strokes

Changes in health practices that will increase risk of illness

Smoking

Drinking

Drugs

Sleeplessness

Exercise less

Brain Response to StressLimbic System• Adds an element of emotion to the experience of

stress• Usually negative emotions: fear, anger, anxiety,

painReticular formation• Communication network that filters messages to

the body• Receives input from all the sensory systems and

determines which sensory information is processed or blocked

• This allows us to selectively attend to specific tasks while ignoring irrelevant information

What sorts of illness does stress cause?

Ulcers

Brady

CHD

Friedman & Rosenman

Hypertension

Cobb & Rose

Monkey

Business Man

Air Traffic Controller

Sources of Stress

Lesson objectives:

Identifying sources of stress

Theory-Assessing own stress levels using SRRS, a way of identifying a link with life events, sources of stress and illness.

Evidence for SRRS

Evaluating this approach

Checking knowledge.

SOURCES OF STRESS

Transactional Model Cox (1978)

LIFE EVENTS

as stressors

Social Readjustment Rating Scale

Holmes and Rahe

Key Study : Rahe et al

stress of life events

Correlationstress related illness

De Longis et al

DAILY HASSLES & UPLIFTS

e.g. rising prices

home maintenance

crime

physical appearance (bad hair day?)

weight

recreation

relations with friends / family

good weather

job promotion

Work Place Stress

Pressures of work Work environment

Key Study : Marmot et al

‘Workplace Stressors’

BURNOUT

NOISE (Glass et al)

Predictability Controllability

Higher Stress?

Control Lack of Control

Langer and Rodin

‘Old Peoples Homes’

Individual DifferencesCan be innate or learned

Weg

Anderson

Cooper et al

Bailey & Dua

Personality – Friedman & Rosenman

Gender

Culture

Hardiness - KobasaTaylorFranken HouserHastrup et alOgdenGyton & Hall

STRESS !

Critical Issue

STRESS MANAGEMENT

Coping (1)

Lazarus and Folkman (1984)• Constantly changing cognitive and behavioural

efforts to manage specific internal and/or external demands that are appraised as taxing or exceeding the resources of the person

Several important elements of the definition:• Coping is a process of constant evaluation of the

success of one’s strategies• Coping is learned as one encounters situations• Coping requires effort• Coping is an effort to manage. Success is not

contingent on mastery, just good enough

Coping (2)Health & energyPositive belief• the ability to cope is enhanced when people believe

they can successfully bring about desired consequences

Problem-solving skills• having specific knowledge or abilities related to

specific problem

Social skill• ability to get other people to cooperateSocial support• feeling of being accepted, loved, or prized by others

Material Resources

Coping (3)Problem Focussed Coping• consists of changing the situation• redefining the problem• looking at alternative solutions• evaluating the implications of the alternatives• choosing the best one to act on

Emotion-focussed coping• consists of controlling and possibly changing the

emotional response to an event• cognitive responses such as avoidance or minimization• the goal is to decrease emotional distress• often used when the individual feels that nothing can be

done about the situation