Stress Flashcards
What is stress?
Stress is any change which can potentially or actually threaten our body’s ability to maintain homeostasis.
What is eustress?
Good, mild stress which allows us to overcome challenges and motivates us such as taking a holiday or doing an exam.
What is distress?
Stress which disease and/or impairs our performance in day to day life, such as death of family or chronic pain.
What are stressors?
Stimulus which produces stress
What are the external stressors?
Physical environment; noise, cramped, temp
Social interactions which may be rude or aggressive
Organisational such as rules and deadlines
Major life events
Daily hassles like commuting
What are life events?
Birth, divorce, work, marriage. These can also be classified as psychosocial events.
What is an internal stress?
Lifestyle choices like caffeine intake
Personality traits such as people pleasing, perfectionism and workaholic
Mindset, like unrealistic expectations
Self criticism
What is a psychosocial event which can be a stressor?
Unemployment, marriage, divorce, new job, financial concern and going to surgery. These overlap with external stressors.
What is a physiological stressor?
Stressor due to harm or threat from our body.
Blood loss
Hypoglycaemia
Damage to bone
Infection
Climate
Surgery
What is general adaptation syndrome?
The body’s physiological response to a stressor in order to maintain or regain homeostasis. This involves activation of the sympathetic nervous system.
What is the first acute phase of stress?
Alarm phase: Stressor is introduced. The body has anti-shock response via the cerebral cortex-> hypothalamus which activate the sympathetic nervous system via catecholeamines noradrenaline and adrenaline.
What are the phases of prolonged stress?
Resistance and exhaustion phase if the is stressor is not resolved. Driven by the HPA axis and neurotransmitters cortisol and aldosterone.
What is the resistance and exhaustion phase?
-> Resistance phase: Body maintains sympathetic activation via the release of cortisol until stressor is resolved.
If this is not resolved, eventually the body’s resources are depleted and lets to
-> Exhaustion phase: Body cannot maintain its function or homeostasis
What is the short term stress response?
Acute response to stressor. Sensory stimuli received in cerebral cortex; cortex acts on the hypothalamus which stimulates activation of the sympathetic nervous response via pre-ganglionic myelinated B neurons acting on paravertebral ganglia and the pre-vertebral ganglia such as the adrenal medulla to cause release of catecholeamines.
Which neurotransmitters are implicated in the short-term stress response?
Pre-ganglionic myelinated B neuron is acetycholine which acts on nictonic receptors on the adrenal medulla. Post ganglionic which acts on the effector muscles are the catecholeamines noradrenaline and adrenaline.
How does the sympathetic system control stress?
Increases HR and BR. Mydriasis (dilation of the pupils), dilation of the coronary arteries, reduced peristalsis, blood is directed towards the heart and skeletal muscles. Glycogenolysis and constriction of the urinary sphincter via muscarinic receptors
What is the hypothalamic-pituitary-adrenal axis?
Connection between the hypothalamus, pituitary gland and the adrenal renal cortex via neurotransmitters
How does the hypothalamus act on the anterior pituitary gland?
In the resistance phase, when the stressor has not been resolved acutely. Neurosecretory cells of the hypothalamus releases corticotropin releasing hormone (CRH) to act on the anterior pituitary gland.
How does the anterior pituitary gland act on the adrenal cortex?
Releases adrenocorticotropic hormone (ACH) which travels in the blood and acts on the adrenal glands to induce the adrenal cortex to release cortisol.
What is the cause and effect of the resistance/adaptation phase?
Cortisol and aldosterone.
What is the effect of cortisol?
It leads to increased glucose levels by reducing glycogenolysis. It increases proteolysis of skeletal muscle stores and gluconeogenesis. It increases lipolysis and causes immune suppression.
