Stress Flashcards
What is the definition of stress
- to emphasis certain words in speech
- a force applied to the body
- emotional or mental pressure
Name some physical stressors
- injury, surgery
- infection, shock
- pain
- exposure in cold
- sustained exercise
What body systems are involved in stress response
- nervous
- endocrine
- immune
What do the effects of stress depend upon
- duration and severity of the stressor
- the effectiveness of any responses
What are the stages in stress
- alarm reaction
- resistance phase
- exhaustion phase
Describe the alarm reaction
- fight, flight, fright response
- physiological effects
Describe the resistance phase
Adapting to stressor
Describe the exhaustion phase
- severe, persistent stress
- responses futile, systems fail
- pathological effects
Describe the acute stress response
- fight, flight or fright response
- essentially a physiological response to a physical threat
- components - neural and hormonal
Describe the components involved in the alarm reaction
Neural - sympathetic nervous system
Hormonal - adrenal glands - adrenaline (adrenal medulla) and corticosteroids (adrenal cortex)
Describe what happens to the sympathetic nervous system
- increased cardiac output, increased heart rate, increased ventricular contractibility
- redistribution of cardiac output, increased flow to muscles, decreased flow to gut and kidney
- metabolic - glycogen breakdown > glucose release, mobilisation of fat stores
Stimulation of adrenaline release
Function of adrenaline in the alarm response
Adrenaline is secreted by the adrenal medulla and is functionally part of the sympathetic nervous system
- prolongs the action of sympathetic nerves - increased cardiac output, redistribution of cardiac output, metabolic effects
What is the function in glucocorticoids in the alarm reaction
- secreted by adrenal cortex
- cortisol is the main stress hormone
- its action complement those of the sympathetic nervous system and adrenaline
- may have harmful effects if its persistently high
What is the metabolic action of cortisol
Increased energy production from glucose, amino acids and fats
Increased protein breakdown
What are the actions of cortisol
- metabolic
- enhances the actions of adrenaline (permissive effect)
- anti-inflammatory actions
- immunosuppression
What are glucocorticoids actions on the immune response
- anti inflammatory and immunosuppressant actions
- they can inhibit the release of prostaglandins and leukotrienes
- inhibit macrophages and helper T lymphocytes
What can corticosteroid therapy be used for
They can be used as anti-inflammatory drugs, for arthritis ect
Describe the action of a corticosteroid drug
The drug will suppress CRH and ACTH release and the natural response is suppressed
Such individuals are at risk during surgical procedures, including dental extractions
Describe the negative feedback control of cortisol
Can act on the anterior pituitary gland to inhibit secretion of ACTH
Can act on the hypothalamus to inhibit secretion of CRH
What is stress analgesia
Pain is diminished during physical stress
Due to release of endogenous opioid peptides, endorphins, enkephalins in the CNS
These suppress nociception and pain
What can contribute to the stress of patients in a dental setting
- anticipation of treatment
- noise of drills
- masks and gowns
- pain increases stress
Size of stress induced effects
Systolic BP - +5-20mmHg
Diastolic BP - + 4-8mmHg
Heart rate - up to +2
Effects of stress in dentists is greater when…
- standing
- complex/difficult procedure
- with anxious patients
- when supervising a students first extraction
Describe what happens if there is a failure to adapt to stress
- adrenal failure
- immunosuppression
- pelvic ulcers
- CVS disease
