Neuroscience of Stress Flashcards
what is stress caused by?
an external trigger of some kind (ex. being told you have a midterm on Friday)
how is anxiety defined?
persistent, excessive worry that a doesn’t go away even in the absence of a trigger
is stress short or long term?
short term
what is the definition of stress?
a psychological and physiological response to a stimulus (stressor)that alters the body’s equilibrium
what are the 2 types of stress?
psychological stressors (ex. deadlines, pressures at school)
physical (ex. infection, injury, hunger)
is some stress good?
yes
what shape of a graph is between arousal and performance?
inverted U curve
when are difficult tasks performed Better?
during low stress levels
when are easy tasks performed better?
during high stress levels
what is the arousal and performance relationship really similar to on the x axis?
cortisol
with increasing levels of cortisol means what?
people have better cognitive function but lower levels of performance (if we have too much or not enough cortisol)
what are the 2 axes that are activated when we have a stress response?
- Immediate response (SAM axis)
- slightly delayed response (HPA axis)
our SAM axis is primarily what?
synaptic
which axis is faster?
SAM axis (almost reflexive)
our HPA axis is primarily what?
hormonal
what is an example of the SAM axis being activated?
walking down the street, stepping off the curb with a truck coming, you immediately step back onto the curb very quickly
why is the HPA axis slightly delayed?
because we have to release multiple different hormones. We have to wait for cortisol to be released
how long can cortisol remain in the body after a stressful response?
days after
what activates the SAM stress response?
amygdala
where does the distress signal travel to after the amygdala?
hypothalamus
what activates the sympathetic nervous system?
locus coeruleus in the brainstem (release of epinephrine and norepinephrine)
what is responsible for releasing epinephrine and norepinephrine?
adrenal medulla
what does the hypothalamus release in the HPA axis ?
CRH
where does CRH travel to after being released from the hypothalamus?
to the pituitary gland
what does the pituitary gland release?
ACTH
where does the ACTH travel to?
it stimulates the adrenal cortex to release cortisol
what is the goal of releasing cortisol?
to release our energy stores to reposed to the stimulus in some way
does the amygdala have strong or weak facility effect on the HPA axis?
really strong (amygdala Is the primitive part of the brain for fear and stress responses)
what can we compare the prefrontal cortex of the brain to? Why?
Pinnochio. Because it is the rational part of the brain. It has an inhibitory role on the stress response
what prevents the hypothalamus and pituitary gland from releasing more hormones?
the adrenal cortex sends information back to let them know the adrenal gland has health with the stressor.
what is the negative feedback loop important for?
allostasis
when we have chronic stress what happens?
we lose our ability to shut off the negative feedback loop
are the physical and psychological stressors processed in the same part of the brain?
no. they are overlapping in some degree
what do physical stressors mostly activate?
autonomic stress responses (SAM axis) for a faster response
what do psychological stressors primarily activate?
the HPA axis
what triggers the SAM axis?
locus cooeruleus
what does the paraventricular nucleus of the hypothalamus trigger?
HPA axis
what structure is the main integrator of stress signals int he brain?
Paraventricular nucleus (PVN)
what is in charge when we are alert and in control?
prefrontal cortex (letting us think clearly and rationally)
what do we get higher levels of when we are stressed?
norepinephrine and dopamine which can quickly weaken our prefrontal cortex
during acute stress, what does control switch to and from?
norepinephrine and dopamine switch the control from the prefrontal cortex to the limbic system
according to a Monk what question can we ask ourselves to determine if our prefrontal or primitive brain has taken over?
“Do I want to feel the way I’m feeling right now?”
what happens when we have chronic stress?
we lose the ability to turn off the HPA axis (turn off negative feedback loop)
what can chronic stress also result in?
the receptors on the hypothalamus and pituitary gland start to become resistant to cortisol
what does allostatic overload consider?
the cumulative effect of stressors on the body in both physiological and pathological situations
when environmental challenges exceed the ability to cope
what can the impact of chronic stress affect?
increase risk for disease and early mortality
what is higher levels of cortisol over the years associated with?
worse cognition among older adults
what can happen to the dendritic complexity in the hippocampus and prefrontal cortex because of chronic stress?
reduced dendritic complexity
what can chronic stress do to the amygdala?
possible hypertrophy
what happens when someone is expose to stress at. younger age?
worse symptoms of chronic stress in those individuals
what mental health conditions is stress strongly associated with?
depression, pTSD, substance use, anxiety
what physiologically happens to people with major depression?
higher cortisol and smaller hippocampal volumes
what Cana chronic stress do to the HPA axis?
it over activates it
how can exercise treat chronic stress?
exercise can downgrade the stress response
according to research, what kind of exercise improved parasympathetic nervous system and HPA regulation?
yoga and tai chi
what happens to the brain from exercise?
increased ray matter volume in the insulation and hippocampus
increased activation in the prefrontal cortex
what effect do mindfulness interventions have on anxiety?
moderate effect
according to a study, did the physiological sigh or meditation improve respiratory rate and mood more?
physiological sigh
