Chapter 12 Flashcards
(27 cards)
What is stress?
A mismatch between what the body/brain anticipate and the challenges actually experienced or felt.
Is all pressure stressful?
No. Being under pressure isn’t always stressful; stress arises from perception and mismatch.
What types of stressors exist?
Psychological (e.g. exams, social tension), physical (e.g. injury), and mixed (e.g. illness + worry).
Why is stress important for survival?
It triggers protective and adaptive responses to deal with unexpected challenges.
Do only humans experience stress?
No, stress responses occur in all organisms, from bacteria to mammals.
What are heat-shock proteins?
Molecules that help repair or degrade damaged proteins to protect cells from dysfunction.
What role does the brain play in stress?
It perceives stress and coordinates physical and hormonal responses.
What information does the brain use to respond to stress?
Cognitive appraisal, hormonal signals, nutrients, inflammatory molecules, and nerve inputs.
What is the ‘fight or flight’ response?
An immediate reaction to danger involving the sympathetic nervous system.
Which chemicals are released during fight or flight?
Noradrenaline (from nerves) and adrenaline (from adrenal glands).
What physical symptoms are caused by fight or flight?
Tingling, sweating, increased pulse and blood pressure, palpitations, goosebumps, gut sensations.
What does the HPA axis stand for?
Hypothalamic-Pituitary-Adrenal axis.
What is the function of the HPA axis?
Coordinates a hormonal stress response involving cortisol release.
What hormone does the hypothalamus stimulate the pituitary to release?
ACTH (adrenocorticotrophin hormone).
What does ACTH do?
Stimulates the adrenal cortex to secrete cortisol.
What are the effects of cortisol?
Raises blood sugar and metabolic fuels, enhances blood pressure, and temporarily suppresses non-urgent functions.
What body functions does cortisol suppress during stress?
Growth, digestion, inflammation, wound healing, and sex.
Where is cortisol feedback mainly received in the brain?
The hippocampus and the amygdala.
What are the two types of cortisol receptors?
MR (low) and GR (high).
When is the MR receptor activated?
By normal levels of cortisol to maintain metabolism and brain function.
What happens when the GR receptor is highly activated?
The hippocampus shuts down to conserve resources; focus shifts to fear learning.
What shape describes the relationship between stress and brain function?
A bell-shaped curve: a little is good, too much is harmful.
How is cortisol linked to depression?
High cortisol levels and hippocampal shrinkage are found in severe depression.
How do antidepressants help in stress-related depression?
They may normalize the HPA axis by adjusting cortisol receptor density.
