382: Stress Respons Basics

1. Key Concepts
1. Our bodies are built to survive
1. Our body is geared to help us cope with any stressor
2. To handle threat and stress, our bodies
1. body is made to help us cope with any stress
2. We can quickly think through situations
3. We can quickly mobilize energy resources in response to perceived threats
4. It’s all about speed
2. Three concepts to focus on (for first paper)
1. Balance (allostasis)
1. Homeostasis versus Allostasis
1. Homeostasis (term for specific systems in the body)
1. Concept of independent bodily systems using negative feedback loops
2. Maintain internal balance
3. Set point
1. 98.6 in the body
4. Local regulation
1. This isn’t body wide but a specific focus in the body controls that
2. Allostasis (Umbrella term that encompasses Homeostasis) 
1. Disrupted Balance Experiment
1. Selye distressed rats and found...
1. enlarged adrenal cortex
2. shrinking of thymus
3. ulcers
2. Allostasis was a way to describe these three global findings
3. Concept of Multiple Interdependent Systems
1. Balance depends on current needs
2. Multiple set points
3. The whole body is involved in adaptive responses
4. Brain regulated
1. The brain is the master organizer of all of these bodily systems
4. “Stability through change”
5. Example
1. Blood Pressure
1. not an independent system
1. affected by sympathetic nervous system, kidney water retention, hormone levels, etc.
2. No Set Point
1. Blood pressure varies by posture, activity, and mood
6. Allostatic Load
1. How do the different stressors accumulate to be the load that is pressing down on your life
2. McEwen
1. “The cost of chronic exposure to environmental challenges
3. Interaction between the severity of the stressor and the resources of the individual (perception of stressor and perception of resources)
2. Perception (perception is key/very important)
1. Stressor and Stress Response
1. Stressor
1. Anything that disrupts allostatic balance
1. Stress Response
2. Bodies attempt to restore allostasis
2. Reactivity and Recovery
1. Reactivity
1. How much the body responds to stress
2. Recovery
1. How quickly or slowly the body recovers to stress
3. Research is showing that recovery seems to be much more important than reactivity
3. Evolutionary Perspective
1. Stress is needed to survive
4. Acute vs Chronic stress
1. Acute stress is good
1. helps you adapt and survive
2. Chronic stress is bad (months to years)
1. This is when your body starts to wear down
2. Anxiety is the great memory killer
5. Physical vs Psychological stress
1. The body doesn’t distinguish between these.  If you think about a dog biting you then your body will respond the same way as if an actual dog were there
2. Literal Brain
1. Another way of saying our thoughts can activate a positive response or a negative response
3. Epigenetics
1. Development and neuroplasticity (we change over time)
1. Our genetic expression is as much a consequence of environment as other things
2. Genes do Not Dictate
1. Development
1. stress impacts physical and psychological development
2. Neuroplasticity
1. Behavior and experience physically alter the brain
3. Stress Response to a Short-Term Crisis
1. Get Energy Now
1. Cortisol
1. Cortisol is not primarily a stress hormone.  It is primarily metabolic hormone but since metabolic system is so important in the stress response cortisol is stressed in stress
2. Increase...
1. heart rate
2. blood pressure
3. breathing rate
4. Kidneys retain water
1. Not to be confused with liquids in your bladder.  You should empty your bladder but your kidneys will still need to retain water
5. move energy where needed
3. Turn off long term projects
1. Certain processes will stop
1. Growth
2. Digestion
3. Reproduction
2. Long term immune function
4. Blunted Pain perception
1. You need to be able to disregard pain so that you can maintain your fight or flight without interruption
2. Example
1. If you twist your ankle
1. When relaxed you ankle will swell
2. If you are stressed and fleeing a foe then your ankle will not swell during flight
5. Increase Cognitive Function
1. Increased oxygen and glucose to the brain
1. Enhanced learning, memory, and recall
4. Acute vs Chronic Psychological Stress
1. Acute Stress Response                           Potential Impact of Chronic Activation
1. Get energy now                   TO        Diabetes
2. Increase blood pressure        TO       Hypertension
3. Turn off long term projects  TO       Ulcer, stress dwarfism
4. Blunted pain perception       TO       Increased pain sensitivity
5. Increased cognitive function TO      Neurotoxicity/dementia
5. Stress and Health
1. Stress does not cause disease but it does:
1. Make us more susceptible and 
2. make disease processes worse
2. With chronic activation stress response can become more damaging than the stressor itself
6. “We have the ability to change the body’s functioning with thought, with emotion, and with memory”