I. Awake at 2:30 am: You’re afraid of cancer,
heart attack, ulcer—not leprosy, dysentery or liver flukes!
A. Different
diseases than a century ago. (1900: pneumonia, tuberculosis, flu, childbirth)
B. Now
we fall apart slowly. Personality,
stressors, social support influence our health.
II. What do you find stressful?
A. Humans:
traffic, family relationships, money worries
B. Zebras
and lions: acute physical stressors:
escaping predators and finding food
C. Chronic
stressors: drought, famine, parasites
D. Psychological
and social stressors (stressors purely
in our heads)
E. Our
bodies’ stress response is great for dealing with acute physical stressors, but
can be disastrous if
activated
all the time.
III.
Physiological stress response
A. Homeostasis—there
is a single optimum level for any measure in your body, and mechanisms to
maintain that level.
B. Allostasis—different
circumstances demand different set points (sleep vs. bungee-jumping).
C. Stressor:
anything that throws your body out of allostatic balance
1. Injury, illness, heat, cold
2. Anticipation of bad things, empathy with others in bad
situation, financial worries, relationships
D. Stress
response: body’s attempt to restore balance
IV.
Hans Selye (insightful and in some ways
inept)
A. Ovarian
extract—what did it do?
1. Inject rats every day—rats got ulcers, enlarged adrenal
glands, & shrunken immune tissues
2. So did control rats!
3. So did others subjected to cold, heat, forced exercise, or
surgical procedures.
B. Stress!
C. General
Adaptation Syndrome
1. Response
to a wide array of stressors
2. It can
make you sick.
3. Rapid
mobilization of energy from storage sites and inhibition of further storage.
a. Glucose, amino acids, and fats pour out
from liver, muscles, and fat cells.
b. Increase in heart rate, breathing, &
blood pressure: rapidly transport oxygen and fuels.
c. Tornado—not a time to repaint the
kitchen!
4. Inhibit
digestion, growth, reproduction, immunity, and pain perception.
5. Memory
and sensory detection improve.
V. Walter Cannon
A. Fight
or flight syndrome—positive response to stressors.
VI. Selye: General Adaptation Syndrome—3 stages
A. Alarm
stage: initial response.
B. Resistance
stage: reattainment of allostatic balance
C. Exhaustion
stage: resources are depleted (every day is an emergency)
1. Not just that the body “runs out of bullets.”
2. Spending so much on bullets depletes the rest of the system.
VII. The stress response itself can become
damaging. (penny-wise and
dollar-foolish)
A. You
will never store surplus energy, fatigue more rapidly, increase chance of a
form of diabetes.
B. Chronically
active cardiovascular system—increased blood pressure, heart disease, and strokes.
C. Stress
dwarfism
D. Reproductive
disorders (irregular menstrual cycles, decreased sperm counts, decreased
libido)
E. Immune
suppression
F. Some
neurons in brain (hippocampus) are destroyed.
VII. 2 elephants on a seesaw: enormous energy
wasted; hard to fix one thing without unbalancing the rest; hard to get off.
IX. Problems with turning on the stress
response
A. Addison’s
disease—can’t secrete glucocorticoids: stressà decreased blood pressure and shock.
B. Shy-Drager
syndrome—impaired secretion of epinephrine and norepinephrine: hard even to
stand up.
X. Problems with turning off the stress
response: increased risk of getting diseases that make you sick.
A. Individual differences, chance for
intervention.