Stress Flashcards
(28 cards)
What systems are activated during stress?
The sympathetic nervous system is stimulated, and the parasympathetic is inhibited during stress
What are common triggers for the stress response?
Being attacked, attacking, hunger, cold, overheating.
What hormones are released by the adrenal medulla during stress?
Adrenaline and some noradrenaline are released by the adrenal medulla during stress
What stimulates the adrenal medulla?
Acetylcholine from pre-ganglionic sympathetic neurons stimulates the adrenal medulla
What hormone does the adrenal cortex release?
Cortisol is released by the adrenal cortex
What hormone stimulates cortisol release?
ACTH from the anterior pituitary, which is stimulated by CRF from the hypothalamus, stimulates the release of cortisol
Which parts of the amygdala activate the stress response?
In the amygdala the central nucleus (homeostatic stress) and medial nucleus (psychogenic stress) activate the stress response
What does the subgenual anterior cingulate cortex (sgACC) do?
The subgenual anterior cingulate cortex indirectly activates the sympathetic nervous system and HPA axis.
What brain regions regulate the HPA axis after stress?
The hippocampus and Dorsal Anterior Cingulate Cortex regulate the HPA after stress
What type of feedback does cortisol exert on the HPA axis?
Cortisol exerts negative feedback on PVN via glucocorticoid receptors
What are key symptoms of major depressive disorder?
Depressed mood, fatigue, sleep issues, appetite changes, lethargy, worthlessness
How is the HPA axis involved in depression?
The HPA axis is often dysregulated, with abnormal cortisol levels in someone with depression
How does chronic stress impact the hippocampus?
Chronic stress reduces receptor sensitivity and damages neurons, impairing feedback in the hippocampus
What feedback loop maintains chronic stress?
Amygdala → HPA Axis → Glucocorticoids → Locus Coeruleus → Amygdala
Maintains chronic stress
How does depression affect sleep?
Someone with depression will have quicker sleep onset, early REM, frequent waking, disrupted patterns.
What evidence supports monoamine involvement in depression?
Reserpine induces depression by depleting monoamines
This supports monoamines involvement in depression
Which monoamines are depleted in chronic stress?
Noradrenaline, serotonin, dopamine are depleted in chronic stress
How do SSRIs work?
SSRIs block serotonin reuptake, increasing its availability in the synapse.
Why don’t SSRIs work immediately?
SSRIs dont work immediately because initial negative feedback by autoreceptors delays effect; adaptation takes ~2 weeks
How does ketamine act as an antidepressant?
Ketamine acts as a NMDA receptor antagonist (like alcohol); seems to increase synapse formation, especially in anterior cingulate cortex
What are ketamine’s long term effects?
Memory/cognitive issues, bladder/kidney damage, abdominal cramps
What defines an anxiety disorder?
Persistent, inappropriate fear/stress >6 months, debilitating.
Name treatments for anxiety.
Therapy, SSRIs, beta-blockers, benzodiazepines.
What do benzodiazepines do?
Benzodiazepines are GABA-A agonists (reinforce inhibitory effects) → reduce anxiety, promote sleep, cause amnesia/muscle relaxation.
