1.83 Stress 1 Flashcards
What is stress
Stress describes pathophysiological changes following exposure to diverse physical/ chemical or emotional challenges
• Encompasses:
i. the input (stress stimuli)
ii. the processing systems (i.e. areas of the brain)
the output (stress response)
what is the behavioural response to stress?
○ Fear
○ Anxiety
○ Alertness (changes in sleep pattern)
○ Changes in cognition (learning and memory)
Stereotyped behaviour - displacement / coping - playing with hair etc.
What is the autonomic response to stress? (sympathetic nervous system)
○ Cardiovascular /respiratory
○ Gastrointestinal
Metabolic and thermoregulatory
What is the Hypothalamo-Pituitary-Adrenal (HPA) response to stress?
Metabolic
Immunological
What is the first sub-division of stimulus of stress and what does it involve?
Psychological - Uncontrolled stress
External - bereavement
Internal - perfectionism
- controlled - self made/wanted
-acute
-chronic
Three stages of Selye’s General Adaptation Syndrome…
- Acute Stress Alarm Reaction “Fight or Flight”
- Episodic Stress Resistance Struggle to overcome
- Chronic Stress Exhaustion Fatigue, irritability, vulnerable to illness
In acute stress what happens when the stressful situation ends?
When the stressful situation ends, endocrine signals switch off the stress response and the body returns to normal
What are the common features of acute stress?
○ Tachycardia and hypertension ○ Increased metabolic rate ○ Reduced gastrointestinal activity ○ Increased alertness Increased levels of adrenaline and adrenal steroids
What is episodic stress?
Extended over-arousal due to repeated acute stress
How can episodic stress present?
○ tendency to be abrupt and irritability may appear as hostility, leading to deterioration in interpersonal relationships
○ persistent tension headaches and migraine
○ common to be short-tempered, irritable, anxious and tense
○ workplace becomes a very stressful environment
combination of sleeplessness and tiredness
What is chronic stress?
• Occurs when an individual fails to see way out of threatening or miserable situation
• Arises from unrelenting demands and pressures for long periods
Many chronic stresses relate to relationships and position in society
How can early childhood experiences change psychological and biological responses?
May stem from traumatic, early childhood experiences - psychological; experiences make you percieve the world as more stressful - physical; HPA axis sensitivity reset
What are the symptoms of chronic stress?
• Emotional distress □ combination of anxiety, depression and anger/irritability - the three stress emotions • Muscular problems □ especially generalised muscle pain and tension headache • Stomach, gut and bowel problems □ e.g. gastric ulceration, IBD • Constant tiredness Increased risk of coronary heart disease
Which type of stress affects the emotions and which affects the mood?
Acute stress - emotion - fear and anger
Chronic stress - mood - depression and grief
What is anxiety?
- A type of stress closely related to fear and involves similar neural circuitry
- It is the physical and psychological response to a perceived threat (as opposed to a real threat which triggers an acute stress response)
- The threat can be physical, social or emotional and may be triggered by a prior experience
Which two brain areas are responsible for mood?
the amygdala, which generates fear in response to danger
the hippocampus, which plays an important part in memory formation as well as in mood and motivation
Which part of the brain is responsible for thought?
Prefrontal cortex
What can the removal hippocampus and amygdala result in, (bilateral medial temporal lobectomy)?
Epilepsy
Where and what is the name of the principle site of noradrenaline synthesis?
Locus coerulus in the brainstem
What is CRH?
• Corticotrophin releasing hormone (CRH) is secreted by the hypothalamus during a stress response
• It is the main regulator of the HPA axis
plays a major role in our physiological adaptations to acute and chronic stress
Where CRH neutrons found?
• CRH neurones are found in many of the areas of the brain associated with stress
• Locus coeruleus
• Paraventricular nucleus of the hypothalamus (PVN)
Central nucleus of the amygdala
Where do CRH releasing neurons project onto?
Hippocampus
Amygdala
Explain activation of CRH and noradrenaline?
Look at PWP
