stress physiology Flashcards
(18 cards)
what are examples of stressors?
Pysical -injury, surgery -infection, shock -pain -exposure to cold -sustained exercise Threats -imprisonment, torture -exams
what body systems are involved in stress?
nervous, endocrine, immune
what do the effects of stress depend on?
duration and severity of the stressor
effectiveness of any responses
what are the stages in stress?
alarm reaction
resistance phase
exhaustion phase
what is the alarm reation?
acute stress response
fight, flight, fright
to physical threat
what is the neural component of the alarm reaction?
sympathetic NS increased cardiac output - increased HR & contractility redistribution of cardiac output -increase-muscles -decrease-gut, kidney metabolic -glycogen breakdown-glucose release -mobilisation of fat stores stimulation of adrenaline release
what are the effects of adrenaline in the hormonal component of the alarm reaction?
adrenaline secreted by adrenal medulla -SNS
adrenaline release augments and prolongs action of sympathetic nerves
-increased cardiac output
-redistribution of cardiac output
-metabolic effects
what are the effects of glucocorticoids in the hormonal component of the alarm reaction?
secreted by adrenal cortex
-steroids eg cortisol- main stress hormone
complements adrenaline actions
what are the actions of cortisol?
metabolic -increased E production -increased protein breakdown enhances actions of adrenaline -permissive effect anti-inflammatory actions immunosuppression
what are glucocorticoid actions on the immune response?
anti-inflammatory
immunosuppressant
inhibit release of prostaglandins and leukotrienes
inhibit macrophages and helper T lymphocytes
what is corticosteroid therapy?
corticosteroids as anti-inflammatories eg arthritis
long-term disrupts normal control mechanisms
supress CRH & ACTH release
what is stress analgesia?
pain is diminished during physical stress
due to release of endogenous opioid peptides, endorphins, enkephalins in CNS
supress nociception and pain
describe the effect of stress on pain in dentistry
pain increases amount of stress local anaesthesia is stressful noise and PPE contributes women have higher HR response stress response greater in children
what are the sizes of stress-induced effects?
systolic BP + 5-20mmHg
diastolic BP + 4-8mmHg
HR up to +20
what causes stress effects for dentist to be greater?
standing
complex procedure
anxious px
supervising 1st extraction
what happens when stressors continue?
coping = adaptation phase not= exhaustion phase
what is the adaptation phase?
stress response diminishes
stressor no longer threat
resistant to stressor
responses effective in removing stressor
what is the exhaustion phase?
failure to adapt acute stress response fails to diminish stressor effects persist: -adrenal failure -immunosuppression -peptic ulcers -CVS disease
