Lecture 19: Stress Flashcards
What is a stressor?
A threatening or demanding event/situation that disrupt homeostasis
What is the stress response?
A coordinated set of physiological, psychological, and behavioural changes triggered by a stressor
What two systems mediate the vertebrate stress response?
The Sympathoadrenergic System (SAS) and the Hypothalamic–Pituitary–Adrenal (HPA) axis.
What does the SAS control and what hormone does it use?
Rapid, short-term responses; uses adrenaline and noradrenaline
What does the HPA axis control and what hormone does it release?
Longer-term responses; releases cortisol and other glucocorticoids
What are the three stages of the General Adaptation Syndrome?
Alarm. Resistance, Exhaustion
What happens during the alarm stage?
Immediate response; activation of SAS and HPA axis, “fight or flight” behaviour, physiological changes like raised heart rate
What happens during the resistance stage?
Stress hormones remain active, body attempts to restore balance and adapt to the stressor.
What happens during the exhaustion stage?
Prolonged stress leads to health issues like muscle wasting, hypertension, immune suppression, and cognitive impairment.
What are some effects of adrenaline during the stress response?
Increases heart rate, blood sugar, blood flow to muscles, dilates pupils and lungs, suppresses digestion.
What are some effects of cortisol during the stress response?
Inhibits growth, reproduction, immunity; increases glucose production and arousal.
What are the systemic stressors?
Physical/actual threats like pain, inflammation, or blood pressure changes.
What are neurogenic stressors?
Anticipated threats like fear of predators or social anxiety.
What did Sapolsky (2005) find in baboons?
Dominant males recover cortisol faster; subordinates have chronically elevated levels.
How do meerkat pups influence stress in adults?
Their begging increases plasma cortisol and feeding efforts from adults.
What is eustress?
Beneficial, short-term stress that is manageable and resolves once the challenge is over.
What is distress?
Chronic or overwhelming stress that leads to negative health outcomes.
What factors influence whether a stressor leads to eustress or distress?
Quality and intensity of the stressor, genetics, personal history, age, emotional state.
What does the Yerkes-Dodson Law describe?
Arousal improves performance up to a point, then decreases it beyond that point.
What is meant by “active” vs “passive” coping strategies?
Active = confronting the stressor; Passive = withdrawal or inaction.
What is Taylor’s “Tend-and-Befriend” theory?
Suggests females often respond to stress by seeking social affiliation; influenced by oxytocin.
What is stress immunisation?
Early mild stress exposure builds resilience to stress later in life.
What did studies on handled rat pups show?
Handled pups had reduced corticosterone as adults; more maternal licking enhanced stress resilience.
