Stress

Question 1

stress

Answer 1

disturbance of homeostasis

Question 2

systemic stressor

Answer 2

pose direct threat to survival

Question 3

processive stressor

Answer 3

psychological, no direct threat
- asssociated w/ threats based on experience

Question 4

__________ is the hub for two overlapping but distinct endocrine systems in stress response

Answer 4

adrenal gland

Question 5

2 systems for stress response

Answer 5

HPA axis and adrenomedullary response

Question 6

adrenomedullary response

Answer 6

immediate, non-specific
- fight or flight Cannon coined it
- catecholamines epinephrine and norepinephrine

Question 7

HPA axis

Answer 7

1. stressor causes CRH release from hypothalamus
2. CRH travels to pituitary to release ACTH
3. ACTH travels through bloodstream to adrenal cortex, targets zona fasciculata to stimulate release of GC’s like cortisol
4. GC’s have many effects and targets

Question 8

Selye’s main findings

Answer 8

1. stress response is universal (same response regardless of type of stressor, and the same across species)
2. chronic stress leads to illness

Question 9

homeostatic concept cannot explain

Answer 9

anticipatory responses

Question 10

allostasis

Answer 10

changing set point for homeostasis, allows us to function within changing conditions
- set points and responses to set points can change

Question 11

example of acute vs chronic stress side effects that are related

Answer 11

acute: increased heart rate
chronic: hypertension

Question 12

chronic stress on brain

Answer 12

affects hippocampus, amygdala, PFC, (etc)
- increase in neuroinflammation, decrease in neurogenesis

Question 13

acute stress on brain

Answer 13

increase brain functioning, increase hippocampal neurogenesis (in rats), enhance memory 2 weeks after stress (integration of new hippocampal neurons into circuits)

Question 14

does stress only affect hormones

Answer 14

no, also nervous and immune systems

Question 15

basal GCs

Answer 15

steroid hormone released from adrenal cortex
- almost all vertebrate cells have receptors for them
- primary in humans is cortisol

Question 16

cortisol

Answer 16

follows daily (diurnal) cycle
- highest right before wake, lowest during day (for us, opposite for mice bc they’re nocturnal)
- increases in response to stress and low blood glucose
- rhythm in adrenal gland is driven by ACTH release, which follows same rhythm

Question 17

Addison’s disease

Answer 17

decrease in cortisol and aldosterone
- damage/dysfunction of adrenal cortex
- weight loss, nausea, etc
- low levels of salt and glucose in blood
- treatment = cortisol agonist like prednisone, increase salt diet if aldosterone levels are low
- higher does in times of illness, injury, or stress

Question 18

Cushing’s disease

Answer 18

increased cortisol levels, increase in blood glucose levels
- weight gain, abdominal obesity, etc.
- treatment depends on cause, poss lower GC medication, surgery for tumours, etc

Question 19

dexamethasone is a cortisol

Answer 19

agonist

Question 20

GC in response to stress

Answer 20

takes longer to release, takes longer to affect targets
- early stress responses not bc of GC’s

Question 21

Munck’s hypothesis

Answer 21

cortisol at low doses (daily basal levels) is permissive, at high doses is suppressive
- same hormone can have different effects based on dose

Question 22

steps after a stressor

Answer 22

• catecholamines - immediate increase in respiration and cardiovascular rates
• immediate release of glucose and oxygen into blood
• epinephrine - delivery of oxygen to tissues
• glucocorticoids replenish energy reserves
• endorphins stop pain responses

Question 23

Type 1

Answer 23

Mineralcorticoid receptors
- high affinity for cortisol
- basal, non-stress

Question 24

Type 2

Answer 24

Glucocorticoid receptors
- low affinity, active when cortisol levels are high, during stress

Question 25

permissive

Answer 25

basal levels of GCs enhance the actions of the first wave of stress-response hormones - lack of GC's sometime before stressor reduces a physiological resposne

Question 26

stimulatory

Answer 26

stress-induced GC levels enhance the actions of the first wave of stress-response hormones - elimination of stress-induced GC levels decreases physiological response to stressor

Question 27

suppressive

Answer 27

stress-induced GC levels inhibit the actions of the first wave of stress-responseive hormones - eliminations of stress-induced GC increases stress response

Question 28

mother rat stress and son testosterone peak

Answer 28

shifter (to earlier), lead to impaired secual behaviour

Question 29

increase LG =

Answer 29

increase in serotonin tone in hippocampus, increase in transcription factor NGFI-A demethylation of GR exon 1, acetylation of histones around GR in hippocampus -> better gene expression, more GR in hippocampus, regulate stress response

Question 30

low LG =

Answer 30

methylation at exon 17 gene region of GR gene, NFGI-A couldn't bind as well = lower GR in hippocampi, worse stress response regulation

Question 31

bullied twin =

Answer 31

increased DNA methylation at CpG8 on SERT = decreased cortisol response