8- Hormones and Stress Flashcards
ACTH released to where to cause cortisol
Adrenal cortex, next to the kidney
What is CRH
Corticotrophin releasing hormone – a small peptide hormone
What is ACTH
A larger peptide hormone
What are Adrenalin and Noradrenalin
Monoamines
Glucocorticoids, such as cortisol and testosterone, oestrogen and non-hormones such as vitamin D are what
Steroids
The effects of monoamines and glucocorticoids lead to what
Many of the adaptive physiological responses to the stress
The relevant monoamine receptors are
The adrenergic alpha and beta receptors
Are steroids fat soluble?
Yes, they can directly penetrate the cell membrane
Steroids act on
Intracellular receptors as well as interact with cell surface receptors
The fast acting stressor activates what
Brain circuits including
- amygdala
- hypothalamus
- brain stem
Fast acting stressor activates which nervous system
The sympathetic division of the autonomous nervous system
The adrenal medulla releases what
Epinephrine into the circulatory system
The release of cortisol is triggered by
ACTH from the pituitary gland
Inability to produce glucocorticoids increases what
- Vulnerability to stress
- Addison’s disease
Acute stressors include what
Painful stimuli
Acute stressors involve a suppression of what
Incoming ‘nociceptive’ information
Acute stressors involve the release of what
- Endogenous opioid peptides
- Monoamines
- Other neurochemical mechanisms
Cottone et al (2009)
Food and stress
-Not receiving an expected reward is stressful and reduces consumption of a usual food
-This effect can be reversed by treatment with a CRH receptor antagonist
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Chronic exposure to stressors (days/weeks), especially early in life, may be associated with
- Loss of the usual feedback control by cortisol on the production and release of CRH and ACTH.
- Cortisol levels remain chronically high.
Chronic exposure to stressors long term effects may include
-Changed hippocampal function and structure
-This is linked to depression
or
-Enhanced feedback, lowered cortisol levels
-This is linked with chronic fatigue syndrome.
Glucocorticoid release leads to
Suppression of inflammation and immune responses
Tissue damage leads to increased release of
Cytokines
- Act at CNS receptors (hypothalamus and elsewhere)
- Produce behavioural effects (feelings of illness and lethargy)
COMT is important in
Degrading dopamine
What does the gene variant ‘Met’ cause
- Lower COMT activity
- Higher dopamine levels
- May also be prone to greater stress responses
What does the gene variant ‘Val’ cause
- May be less disabled by stress and worry
- Require greater activation in CSTC loops during demanding cognitive tasks
Allostasis refers to what
The homeostatic mechanisms that are activated by stress
Allostatic load refers to what
Factors in our lives that influence stress such as
- Trauma
- Physiological stressors
- Day to day stressors
Is stress beneficial
Initially beneficial but potentially become more harmful with long term or chronic stressors
