topic 7 - stress and mood disorders Flashcards
conditions for a stressful response
being attacked
- hunger
- cold
- attacking somebody
- overheating
what nervous system is involved with stress response
sympathetic nervous system
para-sympathetic nervous system is being inhibited
what does the stress response do to the sympathetic nervous system
- constricts blood vessels
- stimulates release of glucose from the liver
- inhibits digestive system in order to get the energy into your bloodstream faster
- inhibits tears and salvation
- relaxes airways so more air can come in
- speeds heartbeat
what neurotransmitter used by the post-ganglionic neurons in the sympathetic nervous system
noradrenaline - makes ur heart beat go faster
adrenal cortex
cortex is the outer layer of the adrenal gland but think of them as seperate glands
- PVN releases CRF
- releases cortisol which is a glucocorticoid
- one of the main functions of cortisol is to release glucose from stores to keep concentration high in the bloodstream
- it is triggered by the arrival of ACTH from the binding to the receptors
- ACTH triggers the enzymes to start making cortisol and releases it into the bloodstream
adrenal medulla as part of the stress response
gets innovation from the pre-ganglionic neurons as part of the sympathetic nevous system which releases acetylcholine onto the adrenal medulla which then releases noradrenaline and adrenaline into the bloodstream
^ triggered by neural signals coming across the pre ganglionic neurons
ACTH
released into the bloodstream by the anterior pituitary gland
- CRF triggers the release of ATCH
- CRF is released by neurons in the hypothalamus (para ventricular nucleus, PVN) and their axons release CRF into the bloodstream
what hormone will peak first when a stress response is active
adrenaline
the two pathways to the two different endocrine logical responses to stress
- sympathetico adrenal medullary axis
- HPA axis - hypothalamo pituitary adrenal axis
activation of the stress response
amygdala:
- central nucleus of the amygdala: involved in homeostatic challenges (physical)
- medial nucleus of the amygdala: in response to psychogenic challenges (emotional, feeling uneasy)
- subgenual anterior cingulate cortex (indirect activation, involved with depression as well)
direct feedback of cortisol on the PVN
- cortisol binds to glucocorticoid receptors
- this triggers the release of endocannibinoids
- these inhibit the release of glutamate from pre-synaptic terminals onto PVN which also means CRF isn’t being stimulated so not being released
- negative feedback
genetic predisposition example
BDNF polymorphism:
- if u have specific type of BDNF you’re more likely:
increased chances of depression
increased sensitivity to stressful life events
increased sensitivity to childhood adversity