STRESS & BEHAVIOUR

1. STRESS AND BEHAVIOUR
AMRUTHA K H
I MSc ZOOLOGY
U.C COLLEGE

2. Stress is a physiological reaction by the body to
challenges posed by the animal’s external environment
as well as changes in the internal environment caused
by diseases, trauma or any other condition that affects
the normal bodily functions detrimentally.
 The body attempts to find equilibrium/balance
(homeostasis) by continuously keeping the stressors
under control by physiological and emotional coping
mechanisms.
If the body fails to cope effectively, positive stress
becomes negative stress.

3. Positive stress is called Eustress while negative is named
Distress.
The body has external and internal senses that perceive
their life-world and those stimuli are interpreted in the
brain as dangerous, harmful, threatening, of no
importance, friendly or any other emotion.
 Based on the specific interpretation in the brain the body
will react to deal with the information sent by the
environment.

5. ADAPTATIONS TO STRESS
Apart from a variety of emotional responses to
environmental stimuli, an animal could also adapt to an
environment that was previously or initially experienced as
stressful.
Different types of unfavorable environments (stressors)
are:-
1.Climatic stress
2. Nutritional stress
3. Internal stress

6. 1.Climatic stress
includes extreme cold, extreme heat, intense solar
radiation etc.

7. 2.Nutritional stress
Food and water deficiencies.

8. 3.Internal stress
pathogens and toxicity.

9. Four fundamental rules involved in animal adaptation
1. Small sized breeds are found in warm areas, while large sized
breeds are found in cool areas.
2. Limbs, tails, ears of animals are longer in warm areas, while
these are shorter in cool areas.
3. Animals belonging to warm, humid regions have more melanin
pigmentation in comparison to the animals belonging to cool and
dry regions which have less melanin pigmentation.
4. Length of hair and localization of adipose tissue are also related
to the environment of the animal.

10. MORPHOLOGICAL AND ANATOMICAL ADAPTATIONS OCCURRING IN
THE ANIMAL
a) Body size and conformation.
b) Mouth cavity, structure of tongue, oral and lingual papillae and
alimentary tract.
(c) Skin color (pigmentation), skin thickness, number and structure
of sweat glands and hair characteristics of integument.
(d) Localization of adipose tissue.

11.  Adapted animals have equilibrium between lipogenesis and
lipolysis of the adipose tissue.
 In case of availability of feed, fat reserves last for several weeks.
 During drought, fatty acids are released into the blood and used
as an energy source or as building components for cellular
proteins.
 Adipose tissue is importance in providing insulation, energy
storage and endogenous thermogenesis varies among species.

12.  Animals defend themselves against heat by decrease in insulation as
a result of vasodilatation of skin areas, increase in evaporation from
skin (sweating) and respiratory passages (panting), decrease in heat
production which occurs as a result of decrease in food intake and
depression of thyroid activity.

13.  Defense against cold is accomplished by conserving heat, more heat
production or by a combination of both.

14. STRESS RELATED HEALTH PROBLEMS
1.HEART DISEASES
 higher risk of high blood pressure and heart problems.
 increase heart rate and blood flow, and causes the release
of cholesterol and triglycerides into the blood stream.
 People who have chronic heart problems need to avoid acute stress

15. 2.ASTHMA
 stress can worsen asthma
 parent's chronic stress might even increase the risk of developing asthma in
their children.
 study looked at how parental stress affected the asthma rates of young
children who were also exposed to air pollution or whose mothers smoked
during pregnancy.
 The kids with stressed out parents had a substantially higher risk of
developing asthma.

16. 3.Diabetes
 Stress can worsen diabetes in two ways.
 First, it increases the likelihood of bad behaviors, such as
unhealthy eating and excessive drinking.
 Second, stress seems to raise the glucose levels of people
with type 2 diabetes directly.

17. 4.Headaches
 Stress is considered one of the most common triggers for headaches.
 As well as migraine.

18. 5.Accelerated aging
 One study compared the DNA of mothers who were under
high stress, they were caring for a chronically ill child, with
women who were not.
 Researchers found that a particular region of the
chromosomes showed the effects of accelerated aging.
 Stress seemed to accelerate aging about 9 to 17 additional
years.
 Other diseases include Gastrointestinal problems,
Premature death, Alzheimer's Disease, Obesity.

19. BASIC CONCEPT OF ENVIRONMENTAL STRESS
 Stressors are environmental factors that cause stress.
 They include biotic factors such as
 food availability,
 the presence of predators
 infection with pathogenic organisms or interactions with
conspecifics
 as well as abiotic factors such as
 temperature,
 water availability
 toxicants.

20. SIGNS OF STRESS
 They are of 2 types :-
1. Physiology
2. Behaviour
Physiology
 Physiological changes during the experiences of immediate
stressors are well defined.
 It includes increases in pulse, blood pressure, respirations
(panting), pupils dilate, more blood flows to the muscles, spleen
enlarges, blood clotting improves and body reserves are broken
down.
 The body prepares for emergency actions.

21. Behaviour
 Panic, destructive behaviour, vocalisation, capitulation or
freezing, over-aggression, attention-seeking behaviour,
compulsive behaviours (stereotypies)
 displacement of behaviour, scanning the environment
continuously, psychosomatic behaviour, depression or
withdrawal, digestive disturbances and lack of libido.

24. THE 3 PHASES OF STRESS

25. THE 3 PHASES OF STRESS
Phase 1 – The Alarm Phase
 Any physical, emotional, or mental upset will cause an instantaneous
reaction by the body to combat the stressor.
 This physical response is well known as the "fight-or-flight" reaction.
 It sends a tremendous burst of adrenaline to all parts of the body—the
blood vessels, heart, stomach, kidneys, lungs, eyes, muscles, and more.
 If the stress is short-term (acute) or not severe ,we quickly recover without
any detrimental effect to the body.
 If the stress is chronic or long-term, the body's resistance is affected,
making us more susceptible to illness or disease.

27. PHYSICAL SYMPTOMS
• A faster heart rate or “pounding heart”
• Faster breathing
• Blood pressure elevates
• Trembling
• Dry mouth
MENTAL SYMPTOMS
 When the adrenalin is released through our body, it also causes a shift in the
area of the brain that has control.
 The logical, rational part of the brain becomes impaired, difficult to think
calmly and rationally
 Example-
• Hard to concentrate
• Mind races very fast

28. EMOTIONAL SYMPTOMS
 The stress hormones cause a shift from the logical rational part of the brain,
over to the limbic system, the area responsible for instincts and emotions.
 become highly emotional and easily spit out words you later regret.
 Examples:
• Cry easily
• Get angry easily
• Become anxious

29. Phase 2 – The Resistance Phase
 the body tries to become balanced (a process called homeostasis).
 You may think you can handle anything because the stress symptoms
noticed in the alarm stage have now calmed down—until you become
completely exhausted.
 As the stress continues, you may suffer with fatigue, sleep problems, and an
overall malaise.
 If you get poor sleep, you may become quite irritable and have difficulty
concentrating or being productive at home or work.
 This creates even more stress and a vicious cycle has started.

30. PHYSICAL SYMPTOMS
• Fatigue
• Tooth grinding
• Low blood sugar (more hunger) or higher blood sugar
• A need for greater sleep
• Insomnia
• Headaches
• Weight gain or weight loss
MENTAL SYMPTOMS
• Worry
• Inability to concentrate
• Forgetfulness/poor memory
• Jump to conclusions quicker

31. EMOTIONAL SYMPTOMS
• Nervous, anxious or irritable
• Bad moods
• apathy, loss of interest in work or personal life
• Begin to experience depression
• Impatience
• Feel not in control

32. Phase 3 – The Exhaustion Phase
 After combating stress for days to weeks, the body shuts down completely.
 Sometimes after days of unending stress, the body succumbs to illness—
either a viral or bacterial infection.
 It is during this exhaustion stage that you may pay the price of abuse with
premature skin aging.
 Chronic or long-term stress depletes the epidermis of water, oxygen, and
vitamin C, as well as increases hormone levels, histamines, and sebum
production.
 While completely unaware of the internal damage from chronic stress, you
will notice how it manifests in skin symptoms such as bumps, excess oil,
breakouts, acne, pimples, and a host of other unsightly conditions.

33. PHYSICAL SYMPTOMS
• Physical exhaustion; no energy.
• Stress hormones in your system shut down non-essential functions like the
digestive, immune, and the reproductive systems.
• Problems with digestion – bloating, constipation, irritable bowel disorder,
• Get sick easily
• Problems with reproduction
• Suppressed thyroid function
• Blood sugar spirals out of control
MENTAL SYMPTOMS
• Unable to concentrate
• Poor memory
• A “why bother” attitude

34. EMOTIONAL SYMPTOMS
• Feeling like you have nothing to give.
• Not caring about anything anymore
• Not engaging in things you do care about
• Feeling like whatever you do is ineffective.
• Distancing yourself from people

35. ACCLIMATION
 When an animal is subjected to changed condition in laboratory,
animal shows compensatory changes to new environment. These
changes are known as acclimation.
 In other words acclimation is adjustment to laboratory conditions.
 Response to a particular environmental factor.

36.  In case of temperature regulation acclimation is of 2 types :-
i) Cold Acclimation
ii) Hot or warm Acclimation
 The body controls its temperature through the hypothalamus.
 Thermo receptors in the skin send signals to the hypothalamus,
which indicate when vasodilatation and vasoconstriction should
occur.

37. Cold
 The human body has two methods of thermogenesis, which produces heat
to raise the core body temperature.
 The first is shivering, which occurs in an unclothed person when the
ambient air temperature is under 25 °C.
 It is limited by the amount of glycogen available in the body.
 The second is non-shivering, which occurs in brown adipose tissue.

38. Heat
 The only mechanism the human body has to cool itself is by sweat
evaporation.
 Sweating occurs when the ambient air temperatures is above 28 °C and
the body fails to return to the normal internal temperature.
 The evaporation of the sweat helps cool the blood beneath the skin.
 It is limited by the amount of water available in the body, which can cause
dehydration.

39. ACCLIMATIZATION
 When humans are exposed to certain climates for extended periods of time,
physiological changes occur to help the individual adapt to hot or cold
climates.
 This helps the body conserve energy.
Examples
In Animals
 Sheep grow very thick wool in cold, damp climates.
 Fish are able to adjust only gradually to changes in water temperature and
quality. Tropical fish sold at pet stores are often kept in acclimatization bag
until this process is complete.
 Lowe & Vance (1995) were able to show that lizards acclimated to warm
temperatures could maintain a higher running speed at warmer temperatures
than lizards that were not acclimated to warm conditions

41. In Humans
 The salt content of sweat and urine decreases as people acclimatize to hot
conditions.
 Humans who migrate permanently to a higher altitude naturally acclimatize
to their new environment by developing an increase in the number
of RBC to increase the oxygen carrying capacity of the blood, in order to
compensate for lower levels of o intake.

42. AVOIDANCE
 In psychology, avoidance coping, escape coping, or cope and avoid is
a maladaptive coping mechanism.
 characterized by the effort to avoid dealing with a stressor.
 Coping refers to behaviors that attempt to protect oneself from psychological
damage.
 Alternatives to avoidance coping include modifying or eliminating the conditions
that gave rise to the problem and changing the perception of an experience in a
way that neutralizes the problem.

43. TYPICAL SIGNS YOU ARE USING AVOIDANCE COPING
1)If you have an uncomfortable feeling, thought, or memory, you are
likely to stop doing the things that is causing it.
2) You avoid attention, including negative attention like others being
upset with you.
3) You put off dealing with things in life that could cause you stress or
have negative outcomes.
4) If a task or project makes you anxious or you can’t see how you’ll
finish, you quit.
5) You might even try to get away from physical sensations.

44. WHY IS AVOIDANCE COPING IMPORTANT TO UNDERSTAND?
 It’s a strong contributing factor to anxiety & depression, and the things that
arise from these two conditions, such as low self-esteem, eating disorder,
and alcohol abuse.
 The positive side of understanding avoidance coping is that it clarifies how
powerful changing the way we respond to stressors can be.
Therapies that help with avoidance coping
 Most types of talk therapies can help with avoidance coping, because they
help you see the ways you think and behave, and why.
 Cognitive Behavioral Therapy
 Acceptance and Commitment Therapy (ACT)

45. TOLERENCE
 In stressful conditions, a person's ability to do the task appropriately with
minimal anxiety level is known as stress tolerance.
 "Stress tolerance makes a person perform even under stressful conditions.“
 Having positive stress tolerance is being able to stay calm without getting
carried away by strong emotions of helplessness and hopelessness.

46.  Everyone has different sensitivity levels to stress.
 There are certain areas of the brain that have receptors for stress chemicals,
the more receptors you have in these areas the less sensitive you are to
stress.
 Someone with a lot of receptors in this area is going to have a high tolerance
for stress.
 People that score high in stress tolerance aren't easy to upset and are less
emotionally reactive to situations. They tend to be calm and collected in the
face of threatening situations.
 Anger, depression, and generally negative emotions are the calling card of
low stress tolerance.
 People that score low in stress tolerance tend to see ordinary situations as
threatening, and minor inconveniences as extremely difficult.

47. Low stress tolerance
High stress tolerance