stress physiology and its impact on human body.ppt

PHYSIOLOGY OF STRESS
DR. SANDEEP KUMAR RAGHUVANSHI

•To understand the stress response,
we must possess a fundamental
knowledge not only of psychology
but of physiology as well. -
George Everly

ETYMOLOGY AND HISTORICAL USAGE
• The term "stress" had none of its contemporary
connotations before the 1920s. It is a form of the
Middle English destresse, derived via Old French from
the Latin stringere, "to draw tight". The word had
long been in use in physics to refer to the internal
distribution of a force exerted on a material body,
resulting in strain. In the 1920s and '30s, biological
and psychological circles occasionally used the term
to refer to a mental strain or to a harmful
environmental agent that could cause illness.

• Walter Cannon used it in 1926 to refer to external
factors that disrupted what he called homeostasis.
• Physiological stress represents a wide range of physical
responses that occur as a direct effect of a stressor
causing an upset in the homeostasis of the body.
• Upon immediate disruption of either psychological or
physical equilibrium the body responds by stimulating
the nervous, endocrine, and immune systems.
• The reaction of these systems causes a number of
physical changes that have both short- and long-term
effects on the body.

• The Holmes and Rahe stress scale was
developed as a method of assessing risk of
disease from life changes. The scale lists
both positive and negative changes that elicit
stress. These include things such as a major
holiday or marriage, or death of a spouse
and firing from a job.

ANS RESPONSES
• Increased central nervous system (CNS) activity
• Increased mental activity
• Increased secretion of adrenaline (epinephrine), noradrenalin and
cortisol into the bloodstream and to every cell in the body
• Increased heart rate
• Increased cardiac output
• Increased blood pressure
• Increased breathing rate
• Breathing airways dilate
• Increased metabolism
• Increased oxygen consumption
• Increased oxygen to the brain
• Bowel and Bladder sphincter close

• Blood is shunted away from the digestive tract and
directed into the muscles and limbs
• Increased muscle contraction, leads to increased
strength
• Increased blood coagulation (blood clotting ability)
• Increased circulation of free fatty acids
• Increased output of blood cholesterol
• Increased blood sugar released by the liver to
nourish the muscles
• Release of endorphins from the pituitary gland
• Pupils of the eyes dilate

• Hair stands on its end
• Blood thins
• Increased brainwave activity
• Sweat glands increase secretion
• Increased secretion from Apocrine glands resulting in foul body odor
• Capillaries under the surface of the skin constrict (which consequently
increases blood pressure)
• Immune system is suppressed
• Constriction of blood vessels, except to running and fighting muscles
• Reproductive and sexual systems stop working normally
• Digestive system stops metabolizing food normally
• Excretory system turns off
• Saliva dries up
• Decreased perception of pain
• Kidneys decrease output

PSYCHOLOGICAL CONCEPTS
Eustress
•Selye published in year 1975 a model dividing stress into eustress
and distress. Where stress enhances function (physical or mental,
such as through strength training or challenging work), it may be
considered eustress. Persistent stress that is not resolved through
coping or adaptation, deemed distress, may lead to anxiety or
withdrawal (depression) behavior.
•The difference between experiences that result in eustress and
those that result in distress is determined by the disparity between
an experience (real or imagined) and personal expectations, and
resources to cope with the stress.Alarming experiences, either real
or imagined, can trigger a stress response.

COPING
• Responses to stress include adaptation, psychological coping
such as stress management, anxiety, and depression. Over the
long term, distress can lead to diminished health and/or
increased propensity to illness; to avoid this, stress must be
managed.
• Stress management encompasses techniques intended to equip
a person with effective coping mechanisms for dealing with
psychological stress, with stress defined as a person's
physiological response to an internal or external stimulus that
triggers the fight-or-flight response. Stress management is
effective when a person uses strategies to cope with or alter
stressful situations.

• There are several ways of coping with stress, such as controlling
the source of stress or learning to set limits and to say "no" to
some of the demands that bosses or family members may make.
• A person's capacity to tolerate the source of stress may be
increased by thinking about another topic such as a hobby,
listening to music, or spending time in a wilderness.
• A way to control stress is first dealing with what is causing the
stress if it is something the individual has control over. Other
methods to control stress and reduce it can be: to not
procrastinate and leave tasks for last minute, do things you like,
exercise, do breathing routines, go out with friends, and take a
break. Having support from a loved one also helps a lot in
reducing stress.

COGNITIVE APPRAISAL
• Lazarus argued that, in order for a psychosocial situation to be
stressful, it must be appraised as such. He argued that cognitive
processes of appraisal are central in determining whether a
situation is potentially threatening, constitutes a harm/loss or a
challenge, or is benign.
• Both personal and environmental factors influence this primary
appraisal, which then triggers the selection of coping processes.
Problem-focused coping is directed at managing the problem,
whereas emotion-focused coping processes are directed at
managing the negative emotions. Secondary appraisal refers to
the evaluation of the resources available to cope with the
problem, and may alter the primary appraisal.

• In other words, primary appraisal includes the
perception of how stressful the problem is
and the secondary appraisal of estimating
whether one has more than or less than
adequate resources to deal with the problem
that affects the overall appraisal of
stressfulness. Further, coping is flexible in that,
in general, the individual examines the
effectiveness of the coping on the situation; if
it is not having the desired effect, s/he will, in
general, try different strategies

ASSESSMENT
• Because the amount of stressors in a person's
life often (although not always) correlates
with the amount of stress that person
experiences, researchers combine the results
of stress and burnout self-tests. Stress tests
help determine the number of stressors in a
person's life, while burnout tests determine
the degree to which the person is close to
the state of burnout. Combining both helps
researchers gauge how likely additional
stressors will make him or her experience
mental exhaustion

HEALTH RISK FACTORS
• Both negative and positive stressors can lead to
stress.The intensity and duration of stress
changes depending on the circumstances and
emotional condition of the person suffering from
it (Arnold. E and Boggs. K. 2007). Some common
categories and examples of stressors include:
• Sensory input such as pain, bright light, noise,
temperatures, or environmental issues such as a
lack of control over environmental circumstances,
such as food, air and/or water quality, housing,
health, freedom, or mobility.

• Social issues can also cause stress, such as struggles with
conspecific or difficult individuals and social defeat, or
relationship conflict, deception, or break ups, and major events
such as birth and deaths, marriage, and divorce.
• Life experiences such as poverty, unemployment,
clinical depression, obsessive compulsive disorder,
heavy drinking,[68]or insufficient sleep can also cause stress.
Students and workers may face performance pressure stress
from exams and project deadlines.
• Adverse experiences during development (e.g. prenatal
exposure to maternal stress,poor attachment histories,
sexual abuse)are thought to contribute to deficits in the
maturity of an individual's stress response systems. One
evaluation of the different stresses in people's lives is the
Holmes and Rahe stress scale.

GENERAL ADAPTATION
SYNDROME
• Physiologists define stress as how the body reacts to a
stressor, real or imagined, a stimulus that causes
stress.Acute stressors affect an organism in the short
term; chronic stressors over the longer term.The
general adaptation syndrome (GAS), developed by
Hans Selye, is a profile of how organisms respond to
stress; GAS is characterized by three phases: a
nonspecific mobilization phase, which promotes
sympathetic nervous system activity; a resistance
phase, during which the organism makes efforts to
cope with the threat; and an exhaustion phase, which
occurs if the organism fails to overcome the threat
and depletes its physiological resources.

STAGE 1
• Alarm is the first stage, which is divided into two phases: the shock phase and
the antishock phase.
• Shock phase: During this phase, the body can endure changes such as
hypovolemia, hypoosmolarity, hyponatremia, hypochloremia, hypoglycemia—the
stressor effect.This phase resembles Addison's disease.The organism's
resistance to the stressor drops temporarily below the normal range and some
level of shock (e.g. circulatory shock) may be experienced.
• Antishock phase:When the threat or stressor is identified or realized, the body
starts to respond and is in a state of alarm. During this stage, the
locus coeruleus/sympathetic nervous system is activated and catecholamines
such as adrenaline are being produced, hence the fight-or-flight response.The
result is: increased muscular tonus, increased blood pressure due to
peripheral vasoconstriction and tachycardia, and increased glucose in blood.
There is also some activation of the HPA axis, producing glucocorticoids (
cortisol, aka the S-hormone or stress-hormone).

STAGE 2
• Resistance is the second stage and increased secretion of
glucocorticoids play a major role, intensifying the systemic
response—they have lipolytic, catabolic and antianabolic effects:
increased glucose, fat and amino acid/protein concentration in
blood. Moreover, they cause lymphocytopenia, eosinopenia,
neutrophilia and polycythemia. In high doses, cortisol begins to
act as a mineralocorticoid (aldosterone) and brings the body to
a state similar to hyperaldosteronism. If the stressor persists, it
becomes necessary to attempt some means of coping with the
stress.Although the body begins to try to adapt to the strains or
demands of the environment, the body cannot keep this up
indefinitely, so its resources are gradually depleted.

STAGE 3
•The third stage could be
either exhaustion or recove
ry:

• Recovery stage follows when the system's compensation
mechanisms have successfully overcome the stressor effect
(or have completely eliminated the factor which caused the
stress).The high glucose, fat and amino acid levels in blood
prove useful for anabolic reactions, restoration of
homeostasis and regeneration of cells.

• Exhaustion is the alternative third stage in the GAS
model.At this point, all of the body's resources are
eventually depleted and the body is unable to maintain
normal function.The initial autonomic nervous system
symptoms may reappear (sweating, raised heart rate,
etc.). If stage three is extended, long-term damage may
result (prolonged vasoconstriction results in ischemia
which in turn leads to cell necrosis), as the body's
immune system becomes exhausted, and bodily
functions become impaired, resulting in
decompensation.

• The result can manifest itself in obvious illnesses, such as
peptic ulcer and general trouble with the digestive system
(e.g. occult bleeding, melena, constipation/obstipation),
diabetes, or even cardiovascular problems (angina pectoris),
along with clinical depression and other mental illnesses

EFFECTS OF CHRONIC STRESS
• Chronic stress is a term sometimes used to differentiate between acute
stress. Definitions differ, and may be along the lines of continual activation of
the stress response, stress that causes an allostatic shift in bodily functions,or
just as "prolonged stress". For example, results of one study demonstrated
that individuals who reported relationship conflict lasting one month or
longer have a greater risk of developing illness and show slower wound
healing. Similarly, the effects that acute stressors have on the immune system
may be increased when there is perceived stress and/or anxiety due to other
events. For example, students who are taking exams show weaker immune
responses if they also report stress due to daily hassles.While responses to
acute stressors typically do not impose a health burden on young, healthy
individuals, chronic stress in older or unhealthy individuals may have long-
term effects that are detrimental to health

IMMUNOLOGICAL
• Acute time limited stressors, or stressors that lasted less than
two hours, results in an up regulation of natural immunity and
down regulation of specific immunity.This type of stress saw in
increase in granulocytes, natural killer cells, IgA, Interleukin 6, and
an increase in cell cytotoxicity. Brief naturalistic stressors elicit a
shift from Th1(cellular) to Th2(humoral) immunity, while
decreased T-cell proliferation, and natural killer cell cytotoxicity.
Stressful event sequences did not elicit a consistent immune
response, however some observations such as decreased T-Cell
proliferation and cytotoxicity, increase or decrease in natural
killer cell cytotoxicity, and an increase in mitogen PHA. Chronic
stress elicited a shirt toward Th2 immunity, as well as decreased
interleukin 2,T cell proliferation, and antibody response to the
influenza vaccine. Distant stressors did not consistently elicit a
change in immune function.

INFECTIOUS
• Some studies have observed increased risk of
upper respiratory tract infection during chronic life stress.
In patients with HIV, increased life stress and cortisol was
associated with poorer progression of HIV.

CHRONIC DISEASE
• A link has been suggested between chronic stress and
cardiovascular disease. Stress appears to play a role in
hypertension, and may further predispose people to other
conditions associated with hypertension. Stress may also
precipitate a more serious, or relapse into abuse of
alcohol. Stress may also contribute to aging and chronic
diseases in aging, such as depression and metabolic
disorders. The immune system also plays a role in stress and
the early stages of wound healing. It is responsible for
preparing the tissue for repair and promoting recruitment of
certain cells to the wound area.Consistent with the fact that
stress alters the production of cytokines, Graham et al. found
that chronic stress associated with care giving for a person
with Alzheimer's disease leads to delayed wound healing.
Results indicated that biopsy wounds healed 25% more slowly
in the chronically stressed group, or those caring for a person
with Alzheimer's disease.

DEVELOPMENT
• Chronic stress has also been shown to
impair developmental growth in children by
lowering the pituitary gland's production of
growth hormone, as in children associated
with a home environment involving serious
marital discord, alcoholism, or child abuse.
• More generally, prenatal life, infancy,
childhood, and adolescence are critical
periods in which the vulnerability to stressors
is particularly high.

PSYCHOPATHOLOGY
• Chronic stress is seen to affect the parts of the brain where memories are
processed through and stored.When people feel stressed, stress hormones
get over-secreted, which affects the brain.This secretion is made up
of glucocorticoids, including cortisol, which are steroid hormones that
the adrenal gland releases, although this can increase storage of flashbulb
memories it decreases long-term potentation (LTP). The hippocampus is
important in the brain for storing certain kinds of memories and damage to
the hippocampus can cause trouble in storing new memories but old
memories, memories stored before the damage, are not lost. Also high
cortisol levels can be tied to the deterioration of the hippocampus and
decline of memory that many older adults start to experience with age.
• Chronic stress also shifts learning, forming a preference for habit
based learning, and decreased task flexibility and spatial working memory,
probably through alterations of the dopaminergic systems. Stress may also
increase reward associated with food, leading to weight gain and further
changes in eating habits. Stress may contribute to various psychosomatic
disorders, such as fibromyalgia, chronic fatigue syndrome, depression,
and functional somatic syndromes.

ACUTE STRESS
• You can probably think of times when your body has responded to a danger
Here are other examples of acute stress in which the demand, danger or
threat is quick, immediate, very real, and usually does not last very long:
• · Giving birth to a baby
• · Driving down the highway and your tire blows
• · Hiking down a trail when you trip and start to tumble down a steep
decline
• · During an earthquake
• · When lightning strikes
• You get the point.Acute stress does happen and in the very short run and in
the right amounts, an appropriate amount of tension is helpful, beneficial, and
may even save your life. However, in reality, these types of experiences are a
rare occurrence in daily life. Unless you happen to work in a high-risk
occupation such as a policeman in the inner city, fireman, or a whitewater
rafting guide, the percentage of our days that include actual threats to our
lives is less than 1% of the time. Contrary to how it may look from watching
the evening news, for most of us our society today is not one where acute
threat or danger is a daily occurrence.

CONCLUSION
• Our body is designed to respond to acute stress in a predicable
manner for survival. This response, the fight-or-flight, or stress
response, is critical for your ability to survive the life-
threatening situations in life. Through the actions of the
autonomic nervous system, your body is programmed for a
response that will protect you from harm.
• In today's world however, many of our challenges are not acute,
physical challenges. Today we are faced with psychological and
social stressors like too much to do, financial debt, concern for a
loved one, loneliness, or unhealthy relationships. Our
physiological response is not well suited to deal with these
types of stressors. There are negative health consequences
when our bodies stay in a state of physiological hyperarousal
without release.
• Understanding concepts such as the fight-or-flight stress
response and the general adaptation syndrome provide you with
the foundation for understanding how relaxation techniques
have the ability to intercept the stress response.

stress physiology and its impact on human body.ppt

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