- Response adapted for short-term, physical emergencies
- Provoked chronically & for psychological stressors (or the mere expectation of)
For the vast majority of beasts on this planet, stress is about a short-term crisis, after which it’s either over with or you’re over with. When we sit around and worry about stressful things, we turn on the same physiological responses—but they are potentially a disaster when provoked chronically.
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Acute stress response
- Rapid mobilize of energy, inhibition of storage
- Halt long-term, high energy cost functions
- Digestion
- Reproduction, sex drive
- Growth & repair
- Immunity
- Analgesia to keep going
Response = more harmful
The army does not run out of bullets. Instead, the body spends so much on the defense budget that it neglects education and health care and social services (okay, so I may have a hidden agenda here). It is not so much that the stress-response runs out, but rather, with sufficient activation, that the stress-response can become more damaging than the stressor itself, especially when the stress is purely psychological.
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Stress → disease → sickness
Thus, medical practitioners often say, in effect, “You feel sick because you have disease X, not because of some nonsense having to do with stress; however, this ignores the stressors’ role in bringing about or worsening the disease in the first place.
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Psychological → brain’s far-reaching effects regulation
You sit in your chair not moving a muscle, and simply think a thought, a thought having to do with feeling angry or sad or euphoric or lustful, and suddenly your pancreas secretes some hormone. Your pancreas? How did you manage to do that with your pancreas? You don’t even know where your pancreas is. Your liver is making an enzyme that wasn’t there before, your spleen is text-messaging something to your thymus gland, blood flow in little capillaries in your ankles has just changed. All from thinking a thought.
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- Activates sympathetic
- Inhibits parasympathetic
HPA axis
Hypothalamus: CRH → pituitary: ACTH → adrenal glands: adrenaline & noradrenaline: vigilance, anxiety
It is now recognized that the base of the brain, the hypothalamus, contains a huge array of those releasing and inhibiting hormones, which instruct the pituitary, which in turn regulates the secretions of the peripheral glands.
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Others
- Glucocorticoids (cortisol): depression ^6e1395
- Endorphin: blunt pain
- Vasopressin 抗利尿素: water retention, blood pressure ↑
Psychological, subconscious pressures, not just physical
Moreover, all sorts of psychological stressors could trigger them, like public speaking, pressured interviews, exams. According to the old dogma, if you had heart disease, you had better worry when you were undergoing physical stress and getting chest pains. Now it appears that, for someone at risk, trouble is occurring under all sorts of circumstances of psychological stress in everyday life, and you may not even know it.
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NYC = risk factor ^9df141
Cardiovascular diseases
- Stress causes blood vessel damage: Status & Heart Disease
- Fatal heart attack: acute shock, threat, grief, recovery, triumph, pleasure
- Extremes trigger same response: predator/prey, hot/cold ^3bcf6b
Metabolism syndrome from chronic energy mobilization
- Insulin ↑ - resistance
- Blood pressure ↑ - hypertension
- Blood glucose ↑ - hyperglycemia
- Blood fat ↑
- Too much LDL, too little HDL
- Abdominal obesity
No one measure is abnormal, but many measures are almost ^0373f6
Appetite
The official numbers are that stress makes about two-thirds of people hyperphagic (eating more) and the rest hypophagic.*
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- Initial decrease, then increase
- CRH quickly decreases appetite
- Cortisol slowly increases it: recovery from stress response, sugary ^a596e2
- Eating disorder
Digestive system
- Shuts down by stress
- Ulcers ^d9aede
- Intermittent > continuous
- Defense against acid weak during recovery eating
Body shape: apple vs pear
- Abdomen: more easily to liver & converted to glucose
- Gluteal: dispersed more equally throughout the body
- Stress → cortisol → abdomen fat ↑ → metabolic syndrome ↑
Growth
- Prenatal
- Fetus starvation → calibrated/imprinted ‘thrifty’ metabolism
- Risk for metabolic syndrome ↑
- Transmitted across generations
- Postnatal: psychological dwarfism
- Proximity to loved one predicts growth
- Affection is biologically essential - absence = most damaging stressor
- Behaviorism: advised against responding ‘too much’
- Harry Harlow’s surrogate soft terrycloth mother
Immune system Patterns of Behavior
- First few minutes: enhances
- An hour: cortisol suppresses
- Recovery from being overly active to baseline
- Chronic cortisol - lower than baseline
- Increase: sensitization
- Decrease: endorphins (very short termed)
- Short-term enhancement
- Chronic impairment (cortisol → hippocampus)
Not getting enough sleep is a stressor; being stressed makes it harder to sleep. Yup, we’ve got a dread vicious cycle on our hands.
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