the end of stress
TRANSCRIPT
STRESS
What does it mean to you?
StressHow do you deal with it?
Understress
Overstress
Eustress Distress
Stress
• Claude Bernard – le milieu internel
Homeostasis
Allostasis : body’s way of dealing with stress
• Allostasis – body’s ability to remain stable by being themselves able to change
Allostatic load
Is the load too heavy?
Allostasis : fight or flight
any changes – major / minor events
getting up in the morning, chasing the bus,
getting fired
Allostasis overload
• child who try but could not write• boss• spouse with chronic illness• physical problems – feet, hand, eyes etc.• poor eating habits• poor sleeping habits• poor interpersonal relationships• over/under exercise• our imagination
Hormonal Reaction
Sleep deprivation
GLUCOSE CORTISOL
Sleep deprivation is
the most common
brain impairment.
William C. Dement (from The Promise of Sleep, 1999, p. 231)
• Claude Bernard – internal balance
• Walter Cannon – emotional stress and health (1914)
• Hans Seyle – (1930s) – signs of generalized response
Seyle’s experiment
• list of stimuli – “nocuous”
heat
cold
pain
fatique
fasting
nervous stress -- immobilization
Hans Seyle experiments
general adaptation syndrome –
alarm reaction
stage of resistance
state of exhaustion
• Whether a stressor is a slight change in posture or a life-threatening assault, the brain determines when the body’s inner equilibrium is disturbed; the brain initiates the actions that restores the balance.
Bruce McEwen
Stress and the Brain
• Allostasis begins in the hypothalamus adrenal glands adrenaline/epinephrine
• adrenalineheart—pump more blood to muscles & organs (less to
extremities)Oxygen – rushes up to the brainHair – stands on end because adrenaline constricts the
blood vessels to the skin thus preventing bleedingFibrinogen – speeds up blood clottingGlugose release – from energy storage as glycogen and
release fatty acids – provide energyRelease endorphins – natural pain killer
How: HPA axis• Hypothalamic – pituitary – adrenal axis (CRH – adreno- cortisol corticotropin corticotropic goes into blood releasing hormone factor) from blood moves thru to kidney the blood to pituitary
• Nervous – hormonal glands – immune system
Cortisol
• -- made from cholesterol
• function: replenish energy depleted from adrenaline rush by converting food to storage forms as glycogen or fat
• makes us hungry
Too much cortisol
• blocks actions of insulin to stimulate muscle to take up glucose
• storage of fat – in abdominal fat
• loss of protein from muscles and converts to fat
• mineral loss from bones
Too much cortisol
• suppress immune system, get sick easier
• short term help deal with infection/injury
Too little cortisol
* rashes, allergies
• autoimmune diseases when immune system attack body’s own health tissue.
Cortisol and the Brain
• Circadian rhythm
• provides us with energy
Cortisol cycle
• Morning -- evening
Cortisol level upset
• abdominal fat
• muscle loss
• bone demineralization
• memory loss
• cognitive problems
Abnormal secretion causes hippocampus and amygdala to overwork
atrophy of brain cells and even brain damage
• Animals can show stress-related wear and tear even in the wild. But in general they tend not to experience allostatic load because once a stressful situation is over, the stress response subsides.
• For the most part, only humans can keep the HPA axis going indefinitely – because of how our faculties of perception, thought, and emotions are produced and how they are connected to stress response.
• Stress begins in the brain.• Bruce McEwan
• Memory –– declarative– episodic– cellular
Hippocampus
• Memory formation vs Memory storage
• Hippocampus – memory formation
• Hippocampus + amygdala => unconscious memory
Amygdala
• our input – visual stimulus amygdala before the visual cortex
Joseph LeDoux
• diff ./. memory from amygdala / hippocampus
• (amygdala - -out of fear;
• hippocampus – memory formation)
• Woman with amnesia – damage to her hippocampus; unable to form new memory
Extinction***
• a repatterning process
• e.g. a rat – sound + shock• sound no shock• sound no fear
• this is so important because it shows that we can re-wire, although depending on the negative experience we have, the rewiring may at times take longer. But the rewiring takes place in the prefrontal lobe.