Stress PhysiologyIs everything we know about stress wrong?

What do Americans die of?For the first time ever, we have the Westernized luxury of dropping dead of stress-related disease.

What is stress and is it necessarily bad? Stress = Nervous system and endocrine system working together to prepare the body for a challenge. Its fundamentally life-sustaining.

Stressors: positive, tolerable, or toxic? your jobmy jobsicknessstarvation lack of sleepscary moviesanxietiesinjuryjob interviewsex

Physiological response to stressThe fight-or-flight sympathetic nervous system response works beautifully to keep you alive.Brain heightened awareness, release of endorphins, dopamine, and other neurotransmittersSkeletal muscle primed for activityNot negative or unpleasant we pay $$ for it

Robert Sapolsky, Stanford UniversityFor 99% of the species on this planet, stress is 3 minutes of screaming terror on the savannah, after which its over or youre over.

Acute versus Chronic StressGood stress is transient. A roller coaster ride that lasts 3 weeks, I would likely pay to get OFF. Long-term stress is THE problem.

General Adaptation SyndromeThe 3-phase long-term stress responseBegins by identifying stressful situation: this is perception and is highly individualized.

First phase: Alarm Phase (the fight or flight response)Primarily an epinephrine/adrenaline response; nervous and hormonalObjective: survivalBodys needs: higher blood flow, oxygen, and nutrient needs to specific places in the body; less nutrients and oxygen to other places

Epinephrine effectsheart rate and stroke volume

Resource allocation: blood and resources to non-essentials like guts, reproductive, and skinblood and resources to heart, brain, lungs, skeletal muscle

Other effects: release stored nutrients from liver and fat into blood stream

send WBCs to battle stations in skin during injury

IF YOURE RUNNING FROM A LION, YOUR BLOOD PRESSURE MAY BE 180/120, BUT YOURE NOT SUFFERING FROM HYPERTENSION, YOURE SAVING YOUR LIFE!

Risk of repeated activation of the sympathetic nervous system

Wear out your vessels, leading to hypertensionIncrease inflammationInadequate nutrient storage

How to counteract these changes? Training and preparationExercise and diet

Second Phase: The Resistance PhasePrimarily a cortisol response; hormonalCortisols objective: keep you alive until things get better, at almost any cost Released every night, OR under long-term stress

Cortisol and the Resistance PhaseCortisol a friend when youre in needkeeps blood glucose levels high and metabolism levels low in non-essential tissues when youre not eatingkeeps you alive during sleep and starvation makes vessels responsive to vasoconstriction commands

Cortisol and the Resistance PhaseCortisol now is the lingering houseguestoverstays its welcomebegins tearing muscle proteins apart for glucose lose muscle masskeeps blood and nutrient levels low to nonessential tissues decrease antibodies, T-cells, lower resistance to disease and cancer

increased predisposition to diabetesmakes you fat, especially in the abdomenincreased ulcer risk (due to decreased resistance to H. pylori)reduces fertility, causes erectile dysfunction

Cortisol, still lingering (cant take a hint) New Research Cortisol and the Brainreduces memory-formation capacity in the hippocampus of the brainincreases activity and size of the amygdala leading to anxiety and sleep disturbancesdecrease in prefrontal cortex mass and activity self-discipline, planning and decision making, doesnt mature until 25-35 You make the most idiotic decisions, which are going to haunt you for the rest of your life, and yet you think theyre brilliant at the time. Thats another effect of chronic stress: Your judgment goes down the tubes.

Net effect? anxious personhigh BPno energy reservesno sexno sleephigher probability of cancerhigher probability of ulcershigher probability of MIcatches every germ that comes aroundhow would this affect a child in his/her growing years?

two possibilitiesHow does it end?

Recovery PhaseThe system works!High nutrient levels and rerouted resources have overcome the threatHomeostasis is restored

Exhaustion PhaseCant overcome the stressorLose negative feedback controlDeath often occursMIcomplications from diabetesshockcanceropportunistic infectionscardiac arrhythmias

But, wait, there IS good news. THE USUAL SUSPECTS WILL HELPSleepNutritionExercise AND .

Want less cortisol? research studies Decreased perception of stress as negative human studies of 29,000 peopleRat studiesHierarchy give the rat another rat to bite after the shock, less cortisolPreparation 10 second warning, less cortisolControl Give the rat a lever that makes him think hes controlling the shock, less cortisolGive the rat a rat buddy in the cage to bond with after the shock MUCH less cortisol, which brings us to

Oxytocinreleased during stress, as well, and makes us seek out social connections

you release less cortisol and more oxytocin in stressful situations if you are connected to other people

oxytocin causes vasodilation

oxytocin repairs damaged cardiac muscle from stress

increases trust

combats inflammation

How do you get more O? Grooming Breastfeeding or childbirthPaying attention to your friendships Helping other peopleCuddling or 20 seconds of skin-skin contactPlay with your kids or even your petsSex and orgasm