Physiology of stress and anxiety L6 Flashcards
stress=
any condition that actually or potentially poses a challenge to the body’s ability to maintain homeostasis
2 types of stress
Eustress
Distress
what is Eustress
mild stress that is useful
what is Distress
unpleasant or disease producing stress
what is a stressor
any stimulus that produces a stress response
external stressor=
physical environment
social interactions
life events
internal stressor=
lifestyle choices
negative self talk
mind
psychosocial events
unemployment
marriage/ divorce
work
physiological events
blood loss
low blood glucose
surgery
what is the general adaptation syndrome
physiological responses to stressors in an attempt to regain homeostasis
3 responses in the stress response
Alarm phase
Resistance phase
Exhaustion phase
short term stress response
stress—> Cerebral cortex—> hypothalamus–> sympathetic NS–> adrenal medulla—> catecholamines
longterm stress response uses
HPA axis
what phase is the short term stress response
alarm phase
what is the short term stress response controlled by
catecholamines (NA and A) released by the adrenal medulla
name general effects of sympathetic NS (4)
mobilisation of glucose increased: HR, RR, energy use
what phase is the HPA axis
resistance/ adaptation phase
HPA axis=
hypothalamus-pituitary-adrenal axis
what does the hypothalamus release
CRH
corticotropin releasing hormone
what does CRH do
activates the anterior pituitary to release ACTH
ACTH=
adrenocorticotropic hormone
where does ACTH travel to
adrenal glands
what does ACTH do to the adrenal glands
stimulates cortisol release
what is cortisol
glucocorticoid
what does Cortisol do (5)
Lipid released into the blood amino acids/ proteins released from muscles increased blood glucose Aldosterone release immuno suppresent
where is aldosterone released from
adrenal cortex
what does aldosterone do
causes retention of sodium, increased water retention, increased Bp
what are Glucocorticoids
a group of hormones of the adrenal cortex released during stress
effect of stress on sex hormone
junior docs have less testosterone
why have an exhaustion phase
resources of the body become so depleted that they cannot sustain the resistance phase
what is the amygdala involved in
the fear response
what does activation of the amygdala central nucleus cause
-long and short term stress response
periaqueductal grey matter
diffuse modulatory system
what does activating the periaqueductal grey matter do
avoidance behaviour
what does the diffuse modulatory system do
increased vigilance
what suppresses the stress response
Hippocampal activation
what stimulates the stress response
amygdala
what can injecting cortisol enhance
memory
what does stress enhance
memory
what is acute stress effect on the immune system
can up regulate immune system
what is chronic stress effect on the immune system
immunosuppression (mediated by glucocorticoids)
what can glucocorticoids be used to treat
arthritis
anxiety=
inappropriate expression of fear
typical anxiety symptom (4)
tension
overactivity of ANS
upset stomach
impending doom
generalised anxiety=
ongoing state of anxiety lacking reason or focus
panic disorder=
brief periods of intense terror and apprehension (panic attack)
panic attack symptoms (5)
shortness of breath hyperventilation heart palpitations chest pain numbness/ tingling fingers
phobias=
strong fears of specific things or situations
OCD=
intrusive thoughts cause anxiety, compulsions neutralise the anxiety
PTSD
anxiety triggered by recall of past stressful experiences
in PTSD what is reduced in size
hippocampus
In PTSD what has abnormal activation
Amygdala
treatment of anxiety
psychological
pharmacological
drug that reduces anxiety short term
Benzodiazepines
e.g of Benzodiazepines
Diazepam (valium)
temazepam
clonazepam
Benzodiazepines mechanism
GABA agonists
e.g of SSRI
Prozac (fluoxetine)
SSRI=
selective serotonin reuptake inhibitor
mechanism of SSRI
prolonged action of serotonin by blocking reuptake
e.g of B-adrenoreceptor agonist
propanolol
what do Beta blockers do
reduce physiological symptoms
