Stress Flashcards
What are the three stages of stress?
alarm stage= fight or flight
resistance stage= physiologic set points stabilize at a higher than normal level
exhaustion stage= resources run out
What are the two hormones that help us adapt or cope to & with stress?
adrenergic (NE & EPI) & cortisol
Where are our adrenergic hormones from? What are they good for physiologically? Cognitively?
sympathetic NS/adrenal medulla
physiologically: ANS & adrenalin keep us alert, increase physiological parameters
cognitively: NE causes shift from focused processing of sensory info to scanning the environment
Where is cortisol from? What is it good for physiologically? Cognitively?
hypothalamic-pituitary-adrenal (HPA) axis
physiologically: short and long term effects, permissive (restore E, helps w/memory, bolsters immune system) & suppressive (first line response, can lead to allergy or autoimmune disorder)
cognitively: adaptation to stress & restores homeostasis
What axis does NE & EPI come from? What about cortisol? What three structures make up the limbic system?
NE/EPI: sympathoadrenal axis
Cortisol: hypothalamic-pituitary-adrenal axis
limbic system: hippocampus, amygdala, limbic cortex
What systems lead to central changes in arousal, appraisal & cognition as well as peripheral physiological changes?
sympathoadrenal axis
hypothalamic-pituitary-adrenal axis
limbic system
What regulates HPA axis? via what?
limbic system regulates HPA axis via PVN of hypothalamus
What does the sympathoadrenal axis come into play with the stress response? How does the limbic system tie into it?
generates short latency, initial part of stress response
limbic interprets negative stimuli and projects it to bed nucelus of stria terminalis (BNST)
What does the BNST do with the stressful/threatening info transmitted from the limbic system?
mediates the info from amygdala to hypothalamus
regulates locus coeruleus directly or via PVN of hypothalamus
What two structures of the brain module the response to the threat (in the sypathoadrenal axis)?
PFC & hippocampus
Where does the locus coeruleus project and what does each projection do?
caudally: activate subunits of sympathetic NS & release NE & EPI from adrenal medulla
rostrally: neuromodultes PFC, hippocampus, amygdala; also goes to LC, & provides feedback resetting of limbic control of ANS
In the sympathoadrenal axis, what two neurotransmitters cause system responses?
EPI & NE from adrenal medulla
EPI causes glucagon release (glucose) from the liver
What are sympathoadrenal axis central responses to acute stress determined by? What happens in a stressful vs non-stressful situation?
type of NE receptor activated by LC
non-stress: LC produces NE= engage high-affinity alpha2 receptors in PFC, hippo, amyg; NE strengthens PFC functions & weakens those of amyg & hippo
stress: responses from amyg increase LC activity; high NE engages lower affinity beta receptors= strengthen amyg & hippo fxn; higher NE shifts PFC from working memory to arousal; hippo & amyg enhanced memory & fear conditioning
