Stress Flashcards
What are the definitions of stress
To emphasise certain words in speech
A force applied to a body causing deformation or strain
emotional or mental pressure
What can be classed as stressors
PHYSICAL
Injury, surgery
Infection, shock
Pain
Exposure to cold
Sustained exercise
THREATS
Imprisonment, torture
Exams …
What body systems interact to cause stress
Nervous
Endocrine
Immune
What do the effects of stress depend on
Duration and severity of the stressor
The effectiveness of any responses
What are the stages of stress
Alarm reaction
Resistance phase
Exhaustion phase
What is the name of the stages in stress
The General Adaption Syndrome
What does the alarm reaction involve
Fight, flight, fright response
Physiological effects
What is the resistance phase
Adapting to stressor
What does the exhuastion phase refer to
Severe, persistent stress
Responses futile; systems fail
Pathological effects
What components are responsible for producing the alarm reaction
Neural: Sympathetic nervous system
Hormonal: adrenal glands:
Adrenaline (adrenal medulla)
Corticosteroids (adrenal cortex)
What affects on the cardiac and metabolic systems does the alarm reaction cause
Increased cardiac output
-increase HR, increase ventricular contractility
Redistribution of cardiac output
-increase flow to muscle; decrease flow to gut, kidney
Metabolic
-Glycogen breakdown - glucose release
-Mobilisation of fat stores (release of free fatty acids)
Stimulation of adrenaline release
Why is adrenaline released in the alarm stress reaction
Adrenaline release augments and prolongs the action of the sympathetic nerves:
-Increased cardiac output
-Redistribution of cardiac output
-Metabolic effects
What hormones are involved in the alarm reaction
Adrenaline
Glucocorticoids (cortisol)
What is the main ‘stress hormone’
Cortisol
Why may cortisol have harmful effects
If secretions are persistently high
What are the actions of cortisol
Metabolic
-Increased energy production from glucose, amino acids and fats
-Increased protein breakdown
Enhances the actions of adrenaline
-This is called a ‘permissive effect’
Anti-inflammatory actions
Immunosuppression
What happens under long term corticosteroid therapy
negative feedback on ACTH
down regulation in number of receptors
Leads to suppression of stress response
What actions do glucocorticoids have on the immune response
Glucocorticoids have anti-inflammatory and immunosuppressant actions
They can inhibit release of prostaglandins and leukotrienes
They inhibit macrophages and helper T lymphocytes
Many patients receive corticosteroid drug therapy
Increased incidence of illness at times of stress
When is corticosteroid therapy considered in dental practice
Some patients take corticosteroids as anti-inflammatory drugs (e.g. arthritis)
Long-term corticosteroid therapy can disrupt the normal control mechanisms
The drug will suppress CRH and ACTH release, and the natural stress response is suppressed
Such individuals are at risk during surgical procedures, including dental extractions
Another reason why the Medical History is so important
What is the process of cortisol release
Stressor
Hypothalamus
CRH (corticotrophin RH)
Anterior pituitary
ACTH (adrenocorticotrophic hormone)
Adrenal cortex
Cortisol
Actions
What is stress analgesia
Pain is dimished during physical stress e.g. sports, battle
What causes stress analgesia
Due to release of endogenous opioid peptides, endorphins, enkephalins in the CNS
These suppress nociception and pain – decreased perception of pain
What factors increase stress in patients
Stress evident in anticipation of treatment
Severity:
-Oral Surgery > scaling
Effects greater in anxious patients and even greater in ‘dental phobics’
Pain increases the amount of stress
Local anaesthesia is stressful
Noise of dental instruments (e.g. drills) can contribute to the stress
Masks and gowns add to the stress
-less human (power imbalance)
Who is affected most by stress
Children
