Chapter 14

Stress and Stressors

The Concept of Stress

Stress A physical and psychological

response to events (stressors) that challenge a persons normal functioning (homeostasis)

Everyone has stress, it’s a normal part of life

The Concept of Stress Stressors

Physical Examples include injury,

physical exertion, noise, overcrowding, excessive heat or cold

Psychological Examples include

interpersonal conflict, isolation, traumatic events, time pressured tasks, peer pressure, expectations of others

Types of Stressors Psychological conflicts

Approach – approach Two attractive choices

Avoidance – avoidance Two unattractive choices

Approach – avoidance One choice with both positive and negative aspects

Double approach – avoidance Two choices – each with positive and negative

features

Types of Stressors Catastrophic Events

earthquakes, combat stress, floods Life Changes

death of a loved one, divorce, loss of job, promotion

Daily Hassles rush hour traffic, long lines, job

stress, burnout

Perceived control

Stressors are seen as especially stressful when we appraise them as both negative and uncontrolled

“Executive Rat” experiment

Perceived Control Health consequences of a loss of control

No connection to shock source

To shock control To shock source

“Executive” rat “Subordinate” rat Control rat

Perceived Control Equality and Longevity

The Stress Response

Physiological response Cerebral cortex perceives and

interprets a stressor (appraisal) Sympathetic nervous system releases

epinephrine and norepinephrine (adrenaline)

Adrenal glands release cortisol

Pituitary hormone in the bloodstream stimulatesthe outer part of the adrenalgland to release the stress hormone cortisol

Sympathetic nervoussystem releases the stress hormonesepinephrine andnorepinephrinefrom nerve endings in the inner part ofthe adrenal glands

Thalamus

Hypothalamus

Pituitary gland

Adrenal glands

Cerebral cortex(perceives stressor)

The Stress Response

Psychological response Appraisal of stress

Primary appraisal – Is this a threat or challenge?

Secondary appraisal – What should I do?

Stress Appraisal

Stressful event(tough math test)

Threat(“Yikes! This isbeyond me!”)

Challenge(“I’ve got to apply

all I know”)

Panic, freeze up

Aroused, focused

Appraisal Response

The Stress Response

Psychological response Appraisal of stress

Primary appraisal Secondary appraisal

Walter Cannon – “fight or flight”

Increases heart rate and respiration

Diverts blood from digestion to skeletal muscles

Dulls pain Releases sugar and fat

from the body’s stores

The Stress Response

Psychological response Appraisal of stress

Primary appraisal Secondary appraisal

Walter Cannon – “fight or flight” Hans Selye – General Adaptation

Syndrome (GAS)

General Adaptation Syndrome – Hans Selye

Stressresistance

Phase 1Alarm

reaction(mobilize

resources)

Phase 2Resistance(cope with stressor)

Phase 3Exhaustion(reservesdepleted)

The body’s resistance to stress canlast only so long before exhaustion sets in

Stressoroccurs