Stress

Question 1

Give some examples of physical stressors

Answer 1

Injury, surgery, infection, shock, pain, exposure to cold, sustained exercise

Question 2

Give some examples of emotional stressors/threats

Answer 2

Imprisonment, torture, exams

Question 3

Which body systems are involved in stress?

Answer 3

Complex interaction between nervous system, endocrine system and immune system

Question 4

What do the effects of stress depend on?

Answer 4

Duration and severity of the stressor

The effectiveness of any responses

Question 5

What are the 3 stages of stress (the General Adaptation Syndrome)?

Answer 5

1. Alarm reaction
2. Resistance phase
3. Exhaustion phase

Question 6

Describe the alarm reaction in stress

Answer 6

Fight, flight or fight response
Physiological response to physical threat
Acute stress response

Question 7

Describe the resistance phase of stress

Answer 7

Adapting to the stressor

Question 8

Describe the exhaustion phase of stress

Answer 8

Occurs in severe, persistent stress
Responses are futile; systems fail
Pathological effects

Question 9

What is the General Adaptation Syndrome?

Answer 9

A there-stage response that the body has to stress: alarm reaction, resistance phase, exhaustion phase

Question 10

Which systems are involved in the alarm reaction (acute stress response)?

Answer 10

Neural: sympathetic nervous system
Hormonal: adrenal glands
Adrenaline (adrenal medulla)
Corticosteroids (adrenal cortex)

Question 11

Describe the neural component of the alarm reaction

Answer 11

Sympathetic nervous system

• Increased cardiac output: increased heart rate, increased ventricular contractility
• Redistribution of cardiac output: increased flow to muscle, decreased flow to gut, kidney
• Metabolic effects: glycogen breakdown -> glucose release, mobilisation of fat stores -> release of free fatty acids
• Stimulation of adrenaline release

Question 12

Describe the adrenaline hormonal component of the alarm reaction

Answer 12

Adrenaline is secreted by the adrenal medulla
Adrenaline release augments and prolongs the action of the sympathetic nerves: increased cardiac output, redistribution of cardiac output, metabolic effects

Question 13

Decrease the corticosteroid hormonal component of the alarm reaction

Answer 13

Glucocorticoids are released from the adrenal cortex
Includes steroids such as cortisol
Cortisol is the main stress hormone
Its actions complement those of the sympathetic NS and adrenaline
May have harmful effects if secretion is persistently high

Question 14

Decrease the actions of cortisol in the stress response

Answer 14

• Metabolic: increased energy production from glucose, amino acids and fats
  Increased protein breakdown
• Enhances the effects of adrenaline: ‘permissive’ effect
• Anti-inflammatory actions
• Immunosuppressive

Question 15

Describe the effects cortisol has on the immune response

Answer 15

• Anti-inflammatory and immunosuppressant actions
• Can inhibit the release of prostaglandins and leukotrienes
• Inhibit macrophages and helper T cells
• Increased incidence of illness at times of stress

Question 16

Describe corticosteroid therapy

Answer 16

• Some patients take corticosteroids as anti-inflammatory drugs (e.g. arthritis)
• Long-term corticosteroid therapy can disrupt normal control mechanisms
• The drug will suppress CRH and ACTH release, and the natural stress response is suppressed

Question 17

Describe the HPA axis in the control of cortisol

Answer 17

• Hypothalamus releases corticotropin releasing hormone (CRH)
• CRH acts on anterior pituitary
• Anterior pituitary releases adrenocorticotropic hormone (ACTH)
• ACTH acts on the adrenal cortex
• Adrenal cortex releases cortisol
• Cortisol has negative feedback effect on release of CRH and ACTH

Question 18

What is ‘stress analgesia’?

Answer 18

When pain is diminished by physical stress e.g. sports, battle
Due to release of endogenous opioids, peptides, enkephalins in the CNS

Question 19

How can we assess stress?

Answer 19

Changes in heart rate and blood pressure

Question 20

Give examples of stressors patients may experience at a visit to the dentist

Answer 20

• Stress depends on the severity of the treatment (extraction > scaling)
• Pain increases amount of stress
• Local anaesthesia is stressful
• Noise of dental instruments contributes to stress
• Masks and gowns add to stress

Question 21

Describe the range of stress-induced changes to BP and HR

Answer 21

Systolic BP = +5-20 mm Hg
Diastolic BP = +4-8 mg Hg
HR = up to +20 bpm

Question 22

When are the effects of stress greater in dentists?

Answer 22

When standing
With complex/difficult procedures
With anxious patients

Question 23

What happens to the individual if the stressors continue to be present?

Answer 23

Either they cope - Adaptation phase

Or they don’t - Exhaustion phase

Question 24

Describe how an individual adapts to the stressor (resistance phase)

Answer 24

With persistent exposure to stressor, the individual’s stress response diminishes
Stressor is no longer seen as a ‘threat’
The individual has become ‘resistant’ to the stressor
Generally happens if the individual’s responses are effective in removing the stressor (or its perceived threat)

Question 25

What happens if an individual fails to adapt to a persistent stressor?

Answer 25

This happens when the acute stress response fails to diminish the stressor
Its effects persist: adrenal failure, immunosuppression, peptic ulcers, CVS decrease
Death in extreme cases

Question 26

Which type of individuals are more prone to high blood pressure and stress-related disease?

Answer 26

Type A individuals