Atielogy And Pathology Flashcards
What is the definition of anxiety
Fearful anticipation of something bad is going to happen
Out of proportion reaction to the stimulus
What is the classic sign of anxiety
The need to avoid situations i.e avoidance of stimulus
‘Feed the fear’
Describe eustress
Acute stress
Normal stress response in response to acute pressure
Describe distress
Chronic stress
Can be a response to a physical or psychological stimulus Fearful anticipation doesn’t subside when the threat subsided
When can distress be classed as a behavioural disorder
When it interferes with normal life
Describe GARD
Excessive and persistent anxiety
Often presents with physical symptoms
Can be a fear of future events, personal safety etc
Describe OCD
Obsessive respective thoughts that are often negative
Counteracted by compulsive behaviours/rituals that pride temporary relief
Describe panic disorder
Brief, acute yet intense panic attacks
Can have similar symptoms of heart attack
How can agoraphobia stem from panic disorders
Fear of certain places due to negative emotions can result in avoidance to prevent panic
Describe phobic disorders
Disproportionate and excessive fear to specific things
Generally predictable there can avoid threat
Describe PTSD
Follows a traumatic event
Symptoms delayed by weeks/months
Re experience of trauma (flashbacks)
Develop avoidance of any sensory cues
Why are some people more likely to develop anxiety disorders
Genetic and environmental influences
Can inherit polymorphisms = genetically predisposed
Early experience of neglect = lack of control
How can behavioural inhibition temperament increase the risk of developing anxiety disorders in children
Will withdraw in unfamiliar situations
Show emotional distress
= low threshold for amygdala arousal
What are the 3 main areas involved in anxiety disorders
CNS, HPA axis (endocrine) , Autonomic
What happens in the amygdala when the stimuli is sensed
Threat is integrated, appraised and a response in co-ordinated
Describe the pathway when external sensory info from the treat is received
Threat -> sensory stimulus -> thalamus -> amygdala -> neurones in baso lateral amygdala
What is the importance of the amygdala in the fear response
involved in the response to innate threat and complex emotional processing
How is a new stimulus appraised and stored in a normal stress response
Amygdala is associated w hippocampus, prefrontal medial cortex and auditory cortex
Allows the stimulus to be associated with an memorial response and stored in pre-frontal cortex
How is a response coordinated in a normal stress response
CRF released by central nucleus of amygdala
Stimulates hypothalamus and locus coeruleus
What is the behavioural response of the striatum and locus coeruleus
Striatum: psychomotor activity
Locus coeruleus: arousal/agitation
What effect does CRF have on behaviour
CRF in LC = increased spontaneous activity
CRF in cerebral aqueduct = increased locomotor activity
What happens if the level of CRF is too high
Inhibits spontaneous activity and locomotor activity
= freezing in response to fear after initial agitation
What role does LC have in response to threat
CRF released from central nucleus of amygdala
= release of noradrenaline that affect vagal nucelei
= parasympathetic effects e.g hypertensions, tachycardia
Describe the HPA axis in endocrine stress response
Amygdala releases CRF -> hypothalamus releases CRF
= pituitary releases ACTH
= adrenal gland release cortisol and adrenaline
= increase sympathetic system
Describe how the negative feedback loop works in anxiety disorders
Usually: negative feedback loop
= cortisol -> gluco/mineralcorticoid receptors _> shut off HPA axis
How does cortisol and CRH levels differ in PTSD and panic disorders
PTSD: increased CRH but decreased cortisol levels
PD: no increase in CRH but increase in cortisol levels
What is the PTSD (Yehuda) hypothesis?
More sensitive to glucocorticoids being released = shut off more quickly
Increased density of glucocorticoid receptors = response to cortisol is more sensitive -> lower cortisol levels
Are noradrenaline levels elevated in people w anxiety disorders?
Yes - noradrenergic response to stress timeline is hypertensive in GAD, PD and PTSD
What noradrenergic receptor has been shown to be dysfunctional in anxiety disorders
A2-adrenoreceptor
Inhibits presynaptic neurotransmitter release
What serotonin receptor is affected in anxiety disorders
5-Ht1a
Inhibitory and located pre and post synaptically
How does 5-HT expression vary with glucocorticoid levels
Chronic stress = decrease 5-HT1a expression
Removal of cortisol (adrenalectomy) = increase 5-HT1a
