1. PHYSIOLOGICAL STRESS
AND
RESPONSE

2. STRESS
What is
stress?
 Pressures, demands
(stressors),
exert force on the body, stress is
the body’s response to this.
 A stress response is an innate,
defensive and adaptive reaction
 Stress levels also depend on
whether the person feels that they
can cope with demands placed on
them or not

3. Stressors
A stressor is a___
physical
chemical
biological agent
environmental condition
event
causes stress to an organism or
disturbances the homeostatsis

4. Homeostasis
The process of
maintaining a
reasonable constant
internal environment
in the body
•
Temperature maintanance of
body
•
37ºC or 98.6 F

5. Acute vs. Chronic Stress
• Acute stress
• Sudden, typically short-lived, threatening event (e.g., robbery,
giving a speech)
• Chronic stress
• Ongoing environmental demand (e.g., marital conflict, work stress,
personality)

6. PHYSIOLOGICAL SYSTEMS
INVOLVED IN THE STRESS
RESPONSE
 The nervous system
 The endocrine system
 The immune system

7. Nervous system
Peripheral nervous system (PNS)
 Consists of all neural pathways to the extremities
 Triggered through the stimulation of sensory nerves
 Triggers a series of involuntary chemical response throughout the
body
Central nervous system (CNS)
 Brain and spinal cord

8. The Endocrine System
The endocrine system is a network of four components:
Glands
Hormones
Circulation
Target organs
Immune system
T-cells found in the form of T-helper and T-suppressor

9. A decade of brain research
•Repeated exposure to cortisol increases aging process of
brain
•Repeated exposure to cortisol damages/ shrinks brain
tissue
•Damage due to repeated exposure to cortisol appears to
be irreversible
•We are “wired for stress” for physical threats yet all
threats set the alarm

10. How does stress cause physical illness?
DIRECTLY
SUPPRESSING THE IMMUNE
SYSTEM
INDIRECTLY
Changes in health practices that will
increase risk of illness
Leucocytes (white blood cells)
 Smoking
Lymphocytes (B Cells or T Cells)
 Drinking
Anti bodies
 Drugs
Natural killer cells
 Sleeplessness
Endorphins
 Exercise less
CARDIOVASCULAR
DISORDERS
Hypertension
Strokes

11. Biopsychosocial Aspect of Stress
• How stress affects health
• Via behavior
• Via physiology

12. Physiological Aspects
• Cardiovascular reactivity – increased blood pressure,
platelets, lipids (cholesterol)
• Endocrine reactivity – increased catecholamines and
corticosteroids
• Immune reactivity – increased hormones impairs immune
function

13. Behavioural Aspects
• Increased alcohol
• Smoking
• Increased caffeine
• Poor diet
• Inattention leading to carelessness

14. Psychophysiological Disorders
• Digestive system – e.g., ulcers, irritable bowel syndrome
• Respiratory system – e.g., asthma
• Cardiovascular system – e.g., hypertension, lipid
disorders, heart attack, angina

15. How to survive?
1) Remove the STRESSOR!
2) EFFECTIVELY Cope with the STRESSOR!

16. Thanks