The Biology of Stress

1
The Biology of Stress
2
Heart Attacks (1 killer)

• Stress elevates the heart rate and constructs the
  blood vessels, which results in high blood
  pressure
• At artery branch points the inner lining of the
  vessel starts to tare, scar and pit.
• Chronic turning on of stress response increases
  the plaque

3
Psychophysiologyical Death

• Wade Davis called it Voodoo Death when studying
  Haiti
• Similarly, pointing the bone is a ritual used by
  Australian Aborigines with the intention of
  injuring or killing their enemies.
• Rage, ecstasy, grief and triumph all have similar
  cardiovascular reactions

4
Metabolism

• Putting in the bank
• Excess of protein, sugars and fat are stored in
  fat cells, muscles and liver. Insulin regulates
  this process
• Sympathetic response decreases insulin and we dip
  into the reserves
• Stress increases the risk of adult onset
  diabetes, one of the most common diseases in the
  west
• Constantly breaking down proteins can cause
  muscles to slightly atrophy over time

5
Digestion

• Takes huge amounts of energy, it stops during
  stress
• Not much appetite during stress (but some people
  actually gain weight when stressed)
• Water is poured into the small intestine and
  removed in the large
• Bowels empty under extreme stress

6
Ulcers

• Peptic (stomach) ulcers can sometimes arise in
  just days if there is an extreme stressor, but is
  most likely formed over time
• Stomach spends a lot of energy not eating itself.
• In stress, less protective mucus is secreted.
  When digestion resumes, it isnt protected at
  first.

7
Growth

• Growth is a nonessential function
• Stress Dwarfism
• Fredrick II of Sicily
• WWII German orphanage study
• JM Barrie
• Touch helps growth
• Even as adults, the body is constantly repairing
  itself

8
Sex and Reproduction

• Reduces sex drive
• Many sexual dysfunctions are a result of stress
  and emotion
• In women it causes disruption to periods, can
  cause fetal asphyxiation
• Sympathetic nervous system is in charge of orgasm

9
Immunity

• An artificial rose can trigger an allergic
  response
• Not only does stress halt immune system, but it
  actively disassembles it
• Israel Yom Kippour War study
• Rats with tumors put in stressful situations

10
Pain

• Soldiers wounded in war
• Recovery rates higher for patients with rooms
  with views
• Runners high

11
Sleep

• Not getting enough sleep is a stressor stress
  makes it hard to sleep (75 of insomnia is caused
  from a major stressor)
• Poor sleepers tent to have greater sympathetic
  arousal
• Death can result from lack of sleep
• People working nights or swing shifts have higher
  stress levels (even if they feel used to it)
• In 1910, the average person slept for 9 hours per
  night. Now the average is 7.5

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• In REM sleep, some parts of the brain are even
  more active than when you are awake. The
  prefrontal cortex is not active, though, which
  disengages the logical part of the brain.
• If you miss a nights sleep, you will have even
  more REM sleep the next night
• Being exposed to lots of new information that day
  is associated with more REM sleep that night -
  REM sleep is important in forming memories and
  problem solving
• Unlike REM sleep, the sympathetic nervous system
  shuts down during slow wave sleep.
  Glutocorticoid and cortisol levels go down. If
  you deprive yourself of sleep, these stress
  hormones actually rise