Chapter 42 Stress and Adaptation
1. Summarize the mechanisms involved in maintaining physiological and psychological
homeostasis.
Stress – a condition in which the human system responds to changes in its normal balanced state
Stressor – anything that is perceived as challenging, threatening or demanding that triggers a stress
reaction
Adaptation – the change that takes place as a result of a stressor
Stress arises mostly from interpersonal relationships and performance demands rather than from actual
physical threats. The perception of stress and responses to it are highly individualized.
Physiologic Stressors
Have a general or specific effect
The specific effect is an alteration of normal body structure and function
The general effect is the stress response
Primary physiologic stressors = chemical agents (drugs, poisons), physical agents (heat, cold
trauma), infectious agents (viruses, bacteria), nutritional imbalances, hypoxia and
genetic/immune disorders
Psychosocial Stressors
Include real and perceived threats
The person’s responses are continuous and include individualized coping mechanisms for
responding to anxiety/guilt/fear/frustration/loss
Examples of common psychosocial stressors = accidents, stressful or traumatic experiences
of family members and friends, horrors of history (Nazi concentration camps), fear of
aggression/mutation (muggings, rape, shootings, terrorism), events of history that are brought
into our homes through Internet and television and rapid changes in the way we live (economic
and political and societal structures)
Homeostasis
Our bodies are always interacting with a constantly changing internal/external environment. The internal
environment must remain in a balanced state.
Homeostasis – various physiologic mechanisms within the body respond to internal changes to maintain
relative constancy in the internal environment
PHYSIOLOGIC HOMEOSTASIS The autonomic nervous system and
endocrine system primarily control
homeostatic mechanisms
Involved to a lesser degree are the
respiratory, cardiovascular,
gastrointestinal and renal systems
Mechanisms are self-regulating,
organized and coordinated
Involuntary
Allostasis – the process of achieving
stability or homeostasis through
physiologic change
Allostatic load – cumulative negative
effects of these physical responses to
prolonged stressors
PYSCHOLOGICAL HOMEOSTASIS Psychological and social changes happen
frequently, and the person’s perception of
these changes may be conscious or
, unconscious
If the person has the necessary
resources, adaptation takes place and
balance is maintained
If resources cannot reestablish
balance, a state of stress results
Adaptation to stress depends on age,
developmental level, past experiences,
support systems and coping mechanisms
2. Explain the interdependent nature of stressors, stress and adaptation.
Adaptation – the change that takes place as a result of a response to a stressor
Adaptation is ongoing as a person strives to maintain balance in the internal/external environments.
Balance is achieved if the perception of the stressful event is realistic and support sources/coping
mechanisms are adequate.
3. Differentiate the physical and emotional responses to stress, including local adaptation syndrome,
general adaptation syndrome, mind-body interaction, anxiety and coping and defense
mechanisms.
Local Adaptation Syndrome
Local adaptation syndrome (LAS) – a localized response of the body to stress
Involves only a specific body part (tissue, organ) instead of the whole body
Stress may be traumatic or pathologic
Short-term adaptive response
Two most common responses = reflex pain response and inflammatory response
REFLEX PAIN RESPONSE Response of the CNS to pain
Rapid and automatic
Protective mechanism to prevent injury
Depends on an intact, functioning
neurologic reflex arc involving sensory
and motor neurons
INFLAMMATORY RESPONSE Local response to injury/infection
Localizes and prevents the spread of
infection
Promotes wound healing
General Adaptation Syndrome
General adaptation syndrome (GAS) – a biochemical model of stress developed by Selye
(1976)
The body’s general response to stress
Three stages
o Alarm reaction
Short-term
Minutes to hours
o Stage of resistance
o Stage of exhaustion
Physiologic response to stress that results from physical/emotional stressors
ALARM REACTION Initiated when a person perceives a
specific stressor and various defense
mechanisms are activated
The hypothalamic-pituitary-adrenal (HPA)
, axis controls the neuroendocrine
response hormone levels rise to
prepare the body to react
Sympathetic nervous system initiates
fight-or-flight response
STAGE OF RESISTANCE The body attempts to adapt to the
stressor
Vital signs, hormone levels and energy
production return to normal
If the stress can be managed or confined,
the body regains homeostasis
If the stressor is prolonged or strong
enough to overwhelm the body’s ability to
defend itself, adaptive mechanisms
become exhausted
STAGE OF EXHAUSTION Adaptive mechanisms can no longer
provide defense
Depletion of resources = damage to the
body with wear-and-tear and systemic
damage
The body rests or mobilizes its defenses
to return to normal…or reaches total
exhaustion and dies
Mind-Body Interaction
You are a nursing student taking a final exam tomorrow and must earn a passing score to pass
the course and remain in the program. After being up most of the night, you cannot swallow food
at breakfast, have a rapid heartbeat and have diarrhea.
This is an example of the relationship between the psychological stressor and physiologic stress
response.
Different reactions happen for everyone with prolonged stress
o Some develop chronic diarrhea, some develop nausea, some develop heart palpitations
Psychosomatic disorders – serious physiologic alterations caused by stress
Anxiety
Anxiety – a vague, uneasy feelings of discomfort/dread with the source being unknown or
unspecific
A feeling of apprehension caused by anticipating a perceived danger
Alerts to danger and enables you to take measures to manage a threat
Fear – a feeling of dread in response to a known threat
MILD ANXIETY Present in day-to-day living
Increases alertness and perceptual fields
Motivates learning and growth, facilitates problem solving
Manifested by restlessness and increased questioning
MODERATE ANXIETY Narrows a person’s perceptual fields so the focus is on immediate concerns
Inattention to other communication and details
Manifested by quavering voice, tremors, increased muscle tension, “butterflies in
the stomach”, slight increases in respirations/pulse
SEVERE ANXIETY A very narrow focus on specific details, causing all behavior to be geared toward
getting relief
Impaired learning ability and easy distraction
Characterized by an extreme fear of a danger that is not real, by emotional
distress that interferes with everyday life and by avoiding situations that cause
anxiety
1. Summarize the mechanisms involved in maintaining physiological and psychological
homeostasis.
Stress – a condition in which the human system responds to changes in its normal balanced state
Stressor – anything that is perceived as challenging, threatening or demanding that triggers a stress
reaction
Adaptation – the change that takes place as a result of a stressor
Stress arises mostly from interpersonal relationships and performance demands rather than from actual
physical threats. The perception of stress and responses to it are highly individualized.
Physiologic Stressors
Have a general or specific effect
The specific effect is an alteration of normal body structure and function
The general effect is the stress response
Primary physiologic stressors = chemical agents (drugs, poisons), physical agents (heat, cold
trauma), infectious agents (viruses, bacteria), nutritional imbalances, hypoxia and
genetic/immune disorders
Psychosocial Stressors
Include real and perceived threats
The person’s responses are continuous and include individualized coping mechanisms for
responding to anxiety/guilt/fear/frustration/loss
Examples of common psychosocial stressors = accidents, stressful or traumatic experiences
of family members and friends, horrors of history (Nazi concentration camps), fear of
aggression/mutation (muggings, rape, shootings, terrorism), events of history that are brought
into our homes through Internet and television and rapid changes in the way we live (economic
and political and societal structures)
Homeostasis
Our bodies are always interacting with a constantly changing internal/external environment. The internal
environment must remain in a balanced state.
Homeostasis – various physiologic mechanisms within the body respond to internal changes to maintain
relative constancy in the internal environment
PHYSIOLOGIC HOMEOSTASIS The autonomic nervous system and
endocrine system primarily control
homeostatic mechanisms
Involved to a lesser degree are the
respiratory, cardiovascular,
gastrointestinal and renal systems
Mechanisms are self-regulating,
organized and coordinated
Involuntary
Allostasis – the process of achieving
stability or homeostasis through
physiologic change
Allostatic load – cumulative negative
effects of these physical responses to
prolonged stressors
PYSCHOLOGICAL HOMEOSTASIS Psychological and social changes happen
frequently, and the person’s perception of
these changes may be conscious or
, unconscious
If the person has the necessary
resources, adaptation takes place and
balance is maintained
If resources cannot reestablish
balance, a state of stress results
Adaptation to stress depends on age,
developmental level, past experiences,
support systems and coping mechanisms
2. Explain the interdependent nature of stressors, stress and adaptation.
Adaptation – the change that takes place as a result of a response to a stressor
Adaptation is ongoing as a person strives to maintain balance in the internal/external environments.
Balance is achieved if the perception of the stressful event is realistic and support sources/coping
mechanisms are adequate.
3. Differentiate the physical and emotional responses to stress, including local adaptation syndrome,
general adaptation syndrome, mind-body interaction, anxiety and coping and defense
mechanisms.
Local Adaptation Syndrome
Local adaptation syndrome (LAS) – a localized response of the body to stress
Involves only a specific body part (tissue, organ) instead of the whole body
Stress may be traumatic or pathologic
Short-term adaptive response
Two most common responses = reflex pain response and inflammatory response
REFLEX PAIN RESPONSE Response of the CNS to pain
Rapid and automatic
Protective mechanism to prevent injury
Depends on an intact, functioning
neurologic reflex arc involving sensory
and motor neurons
INFLAMMATORY RESPONSE Local response to injury/infection
Localizes and prevents the spread of
infection
Promotes wound healing
General Adaptation Syndrome
General adaptation syndrome (GAS) – a biochemical model of stress developed by Selye
(1976)
The body’s general response to stress
Three stages
o Alarm reaction
Short-term
Minutes to hours
o Stage of resistance
o Stage of exhaustion
Physiologic response to stress that results from physical/emotional stressors
ALARM REACTION Initiated when a person perceives a
specific stressor and various defense
mechanisms are activated
The hypothalamic-pituitary-adrenal (HPA)
, axis controls the neuroendocrine
response hormone levels rise to
prepare the body to react
Sympathetic nervous system initiates
fight-or-flight response
STAGE OF RESISTANCE The body attempts to adapt to the
stressor
Vital signs, hormone levels and energy
production return to normal
If the stress can be managed or confined,
the body regains homeostasis
If the stressor is prolonged or strong
enough to overwhelm the body’s ability to
defend itself, adaptive mechanisms
become exhausted
STAGE OF EXHAUSTION Adaptive mechanisms can no longer
provide defense
Depletion of resources = damage to the
body with wear-and-tear and systemic
damage
The body rests or mobilizes its defenses
to return to normal…or reaches total
exhaustion and dies
Mind-Body Interaction
You are a nursing student taking a final exam tomorrow and must earn a passing score to pass
the course and remain in the program. After being up most of the night, you cannot swallow food
at breakfast, have a rapid heartbeat and have diarrhea.
This is an example of the relationship between the psychological stressor and physiologic stress
response.
Different reactions happen for everyone with prolonged stress
o Some develop chronic diarrhea, some develop nausea, some develop heart palpitations
Psychosomatic disorders – serious physiologic alterations caused by stress
Anxiety
Anxiety – a vague, uneasy feelings of discomfort/dread with the source being unknown or
unspecific
A feeling of apprehension caused by anticipating a perceived danger
Alerts to danger and enables you to take measures to manage a threat
Fear – a feeling of dread in response to a known threat
MILD ANXIETY Present in day-to-day living
Increases alertness and perceptual fields
Motivates learning and growth, facilitates problem solving
Manifested by restlessness and increased questioning
MODERATE ANXIETY Narrows a person’s perceptual fields so the focus is on immediate concerns
Inattention to other communication and details
Manifested by quavering voice, tremors, increased muscle tension, “butterflies in
the stomach”, slight increases in respirations/pulse
SEVERE ANXIETY A very narrow focus on specific details, causing all behavior to be geared toward
getting relief
Impaired learning ability and easy distraction
Characterized by an extreme fear of a danger that is not real, by emotional
distress that interferes with everyday life and by avoiding situations that cause
anxiety
