Stress Flashcards
def stressor
anything that knock’s you out of your homeostatic happy place *originates from a survival mechanism
When may your body need stress?
- body needs it to stay alert
- exercise
- fever
What 2 hormones dominate the stress response?
adrenaline (norepinephrine) and cortisol
Who came up with the general adaptation syndrome and what does this mean?
-Selye
- “A common response to all stressors that help mobilize energy to help defeat the threat.”
- proposed stress to be a general response to any unpleasantries (through dropping mice and giving them stomach ulcers)
What physiological “fight/flight” responses do we see?
- increased HR
- increased BP
- increased breathing rate
*body mobilizes stored energy to convert into glucose and fuel muscles that need it
What turns on the “startle” stress response?
- mediated by locus coeruleus
What turns on the “threat” stress response?
- amygdala (responds to strong emotions like fear)
describe the pathway of stress activation
- the amygdala or locus coeruleus independently or collectively activate the hypothalamus (this initiates 2 cascading stress axes that work simulatneously)
- one fast (SAM axis) & 1 slow (HPA axis)
Provide the full name for the SAM axis and how it works:
- sympathetic adreno-medullar axis
- uses sympathetic nerves to activate the adrenal medulla
- fast (bc using nerve responses), first-acting
- activation of AM causes the rush of adrenaline/epinephrine into the blood stream
Why might slower/deep breathing help relax/turn off stress response?
reactivates parasympathetic system (rest + digest)
Provide the full name for the HPA axis and how it works:
- hypothalmic pituitary adrenal axis
- slower bc uses hormones
- once hypothalamus gets activated, it releases CRH (corticotropin releasing hormone) which binds to receptors onthe pituitary gland that release ACTH (adrenocorticotropic hormone)
- ACTH goes through blood to the adrenal cortex which gets activated and releases cortison
- when cortisol rushed into the blood it helps release stored energy (most in liver and fat cells) for fight + flight
*delayed response
Can the hypothalamus and stress responses be activated without the amygdala or locus coeruleus?
Yes! By any alterations in homeostasis
Exercise and psychological stress both activate the same processes… how do these differ in the way they activate it?
Exercise
- voluntary
- acute (mins to hours)
- minor strain
- easy to recover from
Psychological
- involuntary
- chronic - weeks, months, years (ex. money, relationship, work)
- major strain
- difficult to recover from (years with activated SAM and HPA is really straining to body, can cause brain damage)
def the cross-stressor hypothesis
voluntary exercise stress induces adaptations in the stress system that makes us more resilient to all stressors, even physiological ones
What did (Rimmele et al., 2007)’s study find in relation to cortisol, post-test anxiety and heart rate responses to psychosocial stress in trained and untrained men?
lower cortisol (HPA), lower anxiety and lower heart rate (SAM) in trained men
- exercise training = less reactive to stress
what does innocuous mean?
harmless
In a study on kinesophobia by (Pfingsten et al 2001), what was found as a result of telling participants certain exercises would be painful?
- increase in fear rating
- rating of pain increased by 20%
- did not perform as many reps
def nocebo effect
negative effect produced by a sham treatment that cannot be attributed to the properties of the treatment itself and therefore, must be due to the patient’s belief in that treatment
Fear from innocuous cues can be conditioned through _
experience
(ex. Albert became afraid of anything white & fluffy after terrifying noise played with white mouse apprearance)
Equation for fear conditioning of a stress response:
CS (conditioned stimulus) +US (unconditioned stimulus) = CR (Conditioned Response)
CS = harmless stimulus (eventually evokes fear on it’s own)
US = thing that already has fear associated
def generalized anxiety disorder
excessive and exaggerated worry about everyday events for no apparent reason
def panic attacks
A sudden and intense fear that triggers a severe physical reaction when there is no real danger or threat
def phobia
An intense fear or aversion to a specific object or situation that may be harmless
def social anxiety
An intense fear of being negatively judged or scrutinized in a social setting even when it’s not true
How does the amygdala affect neurons?
Links them together strongly, makes it very hard to forget things associated with strong emotions
How does the amygdala function in anxiety and why might this be problematic?
- once any “threat” is detected, the stress response is activated to warn all the body tissues without delay
- the amygdala stays on until the threat is gone (but worries can sometimes never fully go away)
- amygdala also has no way of telling the body what the nature of the threat is, so there may be a heightened response to something that is not truly dangerous.
Are the amygdala and hippocampus necessary for fear conditioning? (Bechara et al 1995)
- Hippocampus not necessary, see similar patterns of fear responses (unless context-related fear)
- Amygdala very critical for fear conditioning
What are the 3 steps for basic fear conditioning?
habituation (CS), acquisition (CS + US = CS), extinction (CS)
What are the 5 steps for context-related fear conditioning?
habituation, acquisition, extinction (change rooms), reinstate, (change rooms), recovery
Linking of fear to context is largely due to _ (brain area)
hippocampus
describe the brain regions involved in fear conditioning
- hippocampus (context-specific threat) activates amygdala to initiate fear, which integrates info and interface with hypothalamus which starts the 2-axis stress response
- the PFC is able to control the more primitive parts of the brain (3 mentioned above) * why mindfulness can help stress, inhibits the amygdala
*in an anxiety disorder, PFC can’t communicate with amygdala anymore
When does learned helplessness happen?
when a person is conditioned to believe that a bad situation is unchangeable or inescapable
*often occurs due to repeated stress, we get freeze instead of fight/flight
describe the shutter box experiment
- 1 side wired with electricity, other side is not
- dog doesn’t even try to cross small barrier because of the uncontrollable stressor
*only dogs shocked without control learn helplessness - dogs shocked with control of a red button to stop shocks escapes
What is the effect of exercise on learned helplessness?
exercising decreases “freeze” responses, take less time to leave (escape latency)
- mice shutter box experiment
More “freeze” responses are associated with _
learned helplessness
