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Flashcards in Stress/HPA Axis Deck (14):
1

2 Main Stress Systems

HPA Axis regulated by CRH, AVP, and ACTH to release cortisol
Sympathetic nervous system regulated by locus ceruleus-NE system to release EPI

2

Psychologic Stressor Pathway

Acts through basolateral nuclei in amygdala to activate hypothalamus (HPA and symp activation), PAG (avoidance behavior), and diffuse modulatory systems (increased vigilance)

3

Physical Stressor Pathway

Bypasses cognitive pathway, just comes in brainstem, goes to bed nucleus of stria terminalis and activates hypothalamus

4

Pathway from Hypothal Activation

Stress activates it to release CRH, acts on ant pit to release ACTH, acts on adrenal gland to release cortisol

5

Parvocellular Neurosecretory Cells

Extend from paraventricular nuc in hypothal into portal and release AVP/CRH from endings to stimulate ant pit

6

2 Neg Feedback Loops

SHORT: ACTH Shuts down paraventricular nuc
LONG: Cortisol shuts down ant pit, paraventricular nuc, and hippocampus/cortex (processing stress)

7

Effect on Chronic Stress

Lose glucocorticoid Rs (GRs) responsible for sensing cortisol neg feedback loop, so you can't shut off stress response. Chronic high stress and depression like syndrome

8

2 Ways Neurons Might Die from Stress

Cortisol might be toxic
BDNF is decreased, required for neuronal growth/maintenance

9

Increased BDNF

Social phobia - bullied mice have

10

Stress and Immune Response Pathway

Stimulates IL1Beta release from lymphocytes, which interact w/ IL1Rs on bvs to release COX, producing PGs. These interact w/ brainstem NE neurons to stimulate hypothal and amygdala

11

HPA Axis and Pregnancy

Decreases in responsiveness leading up to birth. If it doesn't, baby can have low birth rate/higher coronary heart disease

12

Allopregnanolone

From increased P during pregnancy, increases enkaphalins and mu-opioid Rs to decrease NE and block NER

13

Good Stress

Some things like giving a speech actually increased immune system

14

Stress and Telomeres

Chronically stressed individuals had shortened telomeres directly relating to severity and duration of stress. Actually talking about it had relieving effects